nb/sandybridge: Move MRC cache above mrc.bin

This small change greatly reduces CBFS fragmentation. There is now a
small gap of only 728 bytes between mrc.bin and mrc.cache, with the
64 KiB alignment maintained for mrc.cache -- assuming systemagent-r6
is used. The gap was just under 64 KiB before.

With this change, it is easier to accommodate fallback and normal
boot stages without having to manually place the stages in the highly
fragmented CBFS.

Change-Id: Ia2340c1928ed6e232949e053d1943c2f5737f741
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/4763
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@gmail.com>

src/northbridge/intel/sandybridge/Makefile.inc

@@ -47,7 +47,7 @@ $(obj)/mrc.cache:
 
 cbfs-files-$(CONFIG_HAVE_MRC_CACHE) += mrc.cache
 mrc.cache-file := $(obj)/mrc.cache
-mrc.cache-position := 0xfff80000
+mrc.cache-position := 0xfffd0000
 mrc.cache-type := 0xac
 
 $(obj)/northbridge/intel/sandybridge/acpi.ramstage.o : $(obj)/build.h