bootblock: Reduce register load

The common part of the bootblock resets the nvram data if it's found
to be invalid. Since that code is compiled with romcc in i386 mode,
there's a shortage on registers.

Try to reduce the strain by doing things smarter: cmos_write_inner
is the same as cmos_write, just that it doesn't check if the RTC is
disabled. Since we just disabled it before, we can assume that it is so.

Change-Id: Ic85eb2a5df949d1c1aff654bc1b40d6f2ff71756
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/2296
Tested-by: build bot (Jenkins)
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>

src/arch/x86/include/bootblock_common.h

@@ -39,7 +39,7 @@ static void sanitize_cmos(void)
 			int i;
 			cmos_disable_rtc();
 			for (i = 14; i < 128; i++) {
-				cmos_write(cmos_default[i], i);
+				cmos_write_inner(cmos_default[i], i);
 			}
 			cmos_enable_rtc();
 		}