drivers/mrc_cache: move mrc_cache support to drivers

There's nothing intel-specific about the current mrc_cache support.
It's logic manages saving non-volatile areas into the boot media.
Therefore, expose it to the rest of the system for any and all to
use.

BUG=b:69614064

Change-Id: I3b331c82a102f88912a3e10507a70207fb20aecc
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/22901
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/drivers/intel/fsp2_0/memory_init.c

@@ -24,10 +24,10 @@
 #include <fsp/api.h>
 #include <fsp/util.h>
 #include <memrange.h>
+#include <mrc_cache.h>
 #include <program_loading.h>
 #include <reset.h>
 #include <romstage_handoff.h>
-#include <soc/intel/common/mrc_cache.h>
 #include <string.h>
 #include <symbols.h>
 #include <timestamp.h>