tools/Makefile: Compile ncb when CONFIG_NETCONSOLE

Also conditionally add ncb.o to OBJ_FILES list

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>

doc/README.NetConsole

@@ -55,10 +55,8 @@ Again, this script takes exactly one argument, which is interpreted
 as the target IP address (or host name, assuming DNS is working). The
 script can be interrupted by pressing ^T (CTRL-T).
 
-The 'ncb' tool can be found in the tools directory; it will not be
-built by default so you will ither have to adjust the Makefile or
-build it manually.
-
+The 'ncb' tool can be found in the tools directory; it will be built
+when compiling for a board which has CONFIG_NETCONSOLE defined.
 
 For Linux, the network-based console needs special configuration.
 Minimally, the host IP address needs to be specified. This can be

tools/Makefile

@@ -81,6 +81,7 @@ BIN_FILES-$(CONFIG_CMD_NET) += gen_eth_addr$(SFX)
 BIN_FILES-$(CONFIG_LCD_LOGO) += bmp_logo$(SFX)
 BIN_FILES-$(CONFIG_VIDEO_LOGO) += bmp_logo$(SFX)
 BIN_FILES-$(CONFIG_INCA_IP) += inca-swap-bytes$(SFX)
+BIN_FILES-$(CONFIG_NETCONSOLE) += ncb$(SFX)
 
 # Source files which are symlinked from elsewhere in U-Boot
 OBJ_LINKS-y += env_embedded.o
@@ -97,6 +98,7 @@ OBJ_FILES-$(CONFIG_CMD_NET) += gen_eth_addr.o
 OBJ_FILES-$(CONFIG_LCD_LOGO) += bmp_logo.o
 OBJ_FILES-$(CONFIG_VIDEO_LOGO) += bmp_logo.o
 OBJ_FILES-$(CONFIG_INCA_IP) += inca-swap-bytes.o
+OBJ_FILES-$(CONFIG_NETCONSOLE) += ncb.o
 
 # Don't build by default
 #ifeq ($(ARCH),ppc)