doc: Remove any reference to CONFIG_MODEM_SUPPORT, CONFIG_CMD_HWFLOW, CONFIG_HWFLOW and friends from the documentation.

Signed-off-by: David Müller <d.mueller@elsoft.ch>

README

@@ -1023,7 +1023,6 @@ The following options need to be configured:
 		CONFIG_CMD_GO		* the 'go' command (exec code)
 		CONFIG_CMD_GREPENV	* search environment
 		CONFIG_CMD_HASH		* calculate hash / digest
-		CONFIG_CMD_HWFLOW	* RTS/CTS hw flow control
 		CONFIG_CMD_I2C		* I2C serial bus support
 		CONFIG_CMD_IDE		* IDE harddisk support
 		CONFIG_CMD_IMI		  iminfo
@@ -3720,17 +3719,6 @@ FIT uImage format:
 		CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
 		payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
 
-Modem Support:
---------------
-
-[so far only for SMDK2400 boards]
-
-- Modem support enable:
-		CONFIG_MODEM_SUPPORT
-
-- RTS/CTS Flow control enable:
-		CONFIG_HWFLOW
-
 - Interrupt support (PPC):
 
 		There are common interrupt_init() and timer_interrupt()
@@ -3744,22 +3732,6 @@ Modem Support:
 		/ other_activity_monitor it works automatically from
 		general timer_interrupt().
 
-- General:
-
-		In the target system modem support is enabled when a
-		specific key (key combination) is pressed during
-		power-on. Otherwise U-Boot will boot normally
-		(autoboot). The key_pressed() function is called from
-		board_init(). Currently key_pressed() is a dummy
-		function, returning 1 and thus enabling modem
-		initialization.
-
-		If there are no modem init strings in the
-		environment, U-Boot proceed to autoboot; the
-		previous output (banner, info printfs) will be
-		suppressed, though.
-
-		See also: doc/README.Modem
 
 Board initialization settings:
 ------------------------------

doc/README.Modem

@@ -1,72 +0,0 @@
-How to configure modem support in U-Boot :
-
-1. Define modem initialization strings:
----------------------------------------
-
-The modem initialization strings have following format:
-
-	mdm_init1=<AT-command>
-	mdm_init2=<AT-command>
-	...
-
-Turning off modem verbose responses with ATV0 or ATQ1 is not allowed;
-U-Boot analyzes only verbose (not numeric) result codes. Modem local
-command echo can be turned off (ATE0).
-
-2. RTS/CTS hardware flow control:
----------------------------------
-
-You may wish to enable RTS/CTS hardware flow control, if the board's
-UART driver supports it (see CONFIG_HWFLOW compile-time flag in
-config/<board>.h). This is controlled by the 'mdm_flow_control'
-environment variable:
-
-	'mdm_flow_control=rts/cts'  - to enable RTS/CTS flow control.
-	'mdm_flow_control=none '    - to disable.
-
-
-The following are the examples using a Rockwell OEM modem
-configuration:
-
-SAMSUNG # setenv mdm_init1 ATZ			- reset the modem to
-						  the factory defaults.
-SAMSUNG # setenv mdm_init2 ATS0=1               - set modem into
-						  answer mode.
-SAMSUNG # setenv mdm_flow_control rts/cts       - enable serial port
-						  flow control
-SAMSUNG # saveenv
-
-The example above initializes modem into answer mode to wait for the
-incoming call. RTS/CTS flow control is enabled for the serial port.
-(The RTS/CTS flow control is enabled by default on the modem).
-
-
-SAMSUNG # setenv mdm_init1 ATZ
-SAMSUNG # setenv mdm_init2 ATS39=0+IFC=0,0	- disable modem
-						  RTS/CTS flow control
-SAMSUNG # setenv mdm_init3 ATDT1643973         -  dial out the number
-SAMSUNG # setenv mdm_flow_control none
-SAMSUNG # saveenv
-
-The example above initializes modem to dial-up connection on the
-number 1643973. Flow control is disabled.
-
-Note that flow control must be turned both off or both on for the
-board serial port and for the modem.
-
-
-If the connection was set up successfully, the U-Boot prompt appears
-on the terminal console. If not (U-Boot modem was configured for
-originating the call and connection was not established) - the board
-should be reset for another dial-up try.
-
-
-Note on the SMDK2400 board:
----------------------------
-
-Since the board serial ports does not have DTR signal wired, modem
-should be told to ignore port DTR setting prior to connection to the
-SMDK board, and this setting should be stored in modem NVRAM. For the
-Rockwell OEM modem this can to be done with the following command:
-
-AT&D0&W