nvramtool: Unify nvramtool and build_opt_tbl

As cmos.layout parsing capabilities are already there in nvramtool,
use those than using build_opt_tbl.c. Add binary and header file
generation in nvramtool. Make appropriate changes to Makefile.inc.

Change-Id: Iaf3f5d4f51451aeb33c92800a0c895045f2388cf
Signed-off-by: Vikram Narayanan <vikram186@gmail.com>
Reviewed-on: http://review.coreboot.org/898
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
diff --git a/util/nvramtool/layout.h b/util/nvramtool/layout.h
index d99275c0..082c31b 100644
--- a/util/nvramtool/layout.h
+++ b/util/nvramtool/layout.h
@@ -46,10 +46,10 @@
 #define LAYOUT_CHECKSUM_LOCATION_OUT_OF_RANGE (LAYOUT_RESULT_START + 9)
 
 typedef enum {
-	CMOS_ENTRY_ENUM,
-	CMOS_ENTRY_HEX,
-	CMOS_ENTRY_STRING,
-	CMOS_ENTRY_RESERVED
+	CMOS_ENTRY_ENUM = 'e',
+	CMOS_ENTRY_HEX = 'h',
+	CMOS_ENTRY_STRING = 's',
+	CMOS_ENTRY_RESERVED = 'r',
 } cmos_entry_config_t;
 
 /* This represents a CMOS parameter. */