Build: Add "board options" column to boards.cfg

There are some boards where it's currently not possible to detect all
board information at runtime, therefore a new column was added to
boards.cfg .

This column can contain multiple options: a board configuration name,
optionally followed by a colon (':') and a list of options, which are
separated by comma (',').

In case of simple options like '256M_U_BOOT', these expand to
"#define CONFIG_MK_256M_U_BOOT 1" in config.h . In case of
assignments like 'RAM=8192', these expand to "#define CONFIG_MK_RAM
8192" in config.h .

Example:

	FOO:HAS_BAR,BAZ=64

means:
	- the name of the board config file is include/configs/FOO.h
	- the generated file include/config.h will contain these
	  lines:

		#define CONFIG_HAS_BAR  1
		#define CONFIG_BAZ  64

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>

[wd@denx.de: edited commit message; added code to deal with an
optional board configuration name]

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/boards.cfg b/boards.cfg
index 5dd7209..cb1ee31 100644
--- a/boards.cfg
+++ b/boards.cfg
@@ -17,8 +17,8 @@
 #
 #	:.,$! sort -f -k2,2 -k3,3 -k6,6 -k5,5 -k1,1
 #
-# Target	ARCH	CPU		Board name	Vendor		SoC
-###########################################################################
+# Target	ARCH	CPU		Board name	Vendor		SoC		Options
+###############################################################################################
 
 qong		arm	arm1136		-		davedenx	mx31
 mx31ads		arm	arm1136		-		freescale	mx31