ARM: am335x: Add support for chiliSOM

chiliSOM is a System On Module (http://http://grinn-global.com/chilisom/).
It can't exists on its own, but will be used as part of other boards.

Hardware specification:
 * TI AM335x processor
 * 128M, 256M or 512M DDR3 memory
 * up to 256M NAND

We place source inside arch/arm/mach-omap2/ directory and make it
possible to reuse initialization code (i.e. DDR, NAND init) for all
boards that use it.

Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/mach-omap2/am33xx/Kconfig b/arch/arm/mach-omap2/am33xx/Kconfig
index ae1c3cf..82e9541 100644
--- a/arch/arm/mach-omap2/am33xx/Kconfig
+++ b/arch/arm/mach-omap2/am33xx/Kconfig
@@ -1,5 +1,9 @@
 if AM33XX
 
+config AM33XX_CHILISOM
+	bool
+	select SUPPORT_SPL
+
 choice
 	prompt "AM33xx board select"
 	optional