boot: remove cbmem_post_handling()

The cbmem_post_handling() function was implemented by 2
chipsets in order to save memory configuration in flash. Convert
both of these chipsets to use the boot state machine callbacks
to perform the saving of the memory configuration.

Change-Id: I697e5c946281b85a71d8533437802d7913135af3
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/3137
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/northbridge/intel/haswell/haswell.h

@@ -237,8 +237,6 @@ struct mrc_data_container {
 
 struct mrc_data_container *find_current_mrc_cache(void);
 #if !defined(__PRE_RAM__)
-void update_mrc_cache(void);
-
 #include "gma.h"
 int init_igd_opregion(igd_opregion_t *igd_opregion);
 #endif