am57x: Move CONS_INDEX to Kconfig

- Move the CONS_INDEX selection out of CONFIG_SYS_EXTRA_OPTIONS and
      into Kconfig proper.
    - Edit the relevant am57x configs to remove the now unneeded
      CONFIG_SYS_EXTRA_OPTIONS.

Signed-off-by: Daniel Allred <d-allred@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

board/ti/am57xx/Kconfig

@@ -9,6 +9,15 @@ config SYS_VENDOR
 config SYS_CONFIG_NAME
 	default "am57xx_evm"
 
+config CONS_INDEX
+        int "UART used for console"
+        range 1 6
+        default 3
+        help
+          The AM57x (and DRA7xx) SoC has a total of 6 UARTs available to it.
+          Depending on your specific board you may want something other than UART3
+          here.
+
 source "board/ti/common/Kconfig"
 
 endif

configs/am57xx_evm_defconfig

@@ -7,7 +7,6 @@ CONFIG_SPL_STACK_R_ADDR=0x82000000
 CONFIG_DEFAULT_DEVICE_TREE="am57xx-beagle-x15"
 CONFIG_SPL=y
 CONFIG_SPL_STACK_R=y
-CONFIG_SYS_EXTRA_OPTIONS="CONS_INDEX=3"
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set
 CONFIG_CMD_GPIO=y

configs/am57xx_evm_nodt_defconfig

@@ -2,7 +2,6 @@ CONFIG_ARM=y
 CONFIG_OMAP54XX=y
 CONFIG_TARGET_BEAGLE_X15=y
 CONFIG_SPL=y
-CONFIG_SYS_EXTRA_OPTIONS="CONS_INDEX=3"
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set
 CONFIG_CMD_GPIO=y