arm, davinci: add NOR Boot Configuration Word

to add the "NOR Boot Configuration Word" on AM18xx based boards,
define CONFIG_SYS_DV_NOR_BOOT_CFG.

Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Paulraj Sandeep <s-paulraj@ti.com>
Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
diff --git a/doc/README.davinci b/doc/README.davinci
index 0204372..5f1bdc8 100644
--- a/doc/README.davinci
+++ b/doc/README.davinci
@@ -139,3 +139,12 @@
 7) TI DA850 EVM
 http://focus.ti.com/docs/prod/folders/print/omap-l138.html
 http://www.logicpd.com/products/development-kits/zoom-omap-l138-evm-development-kit
+
+Davinci special defines
+=======================
+
+CONFIG_SYS_DV_NOR_BOOT_CFG:	AM18xx based boards, booting in NOR Boot mode
+				need a "NOR Boot Configuration Word" stored
+				in the NOR Flash. This define adds this.
+				More Info about this, see:
+				spraba5a.pdf chapter 3.1