soc/intel/broadwell: remove CACHE_MRC_SETTINGS option

The CPU_SPECIFIC_OPTIONS already auto-selects the option. There's
no point in having a selectable option that is already selected.
There's already an option to select it within intel/common.

BUG=b:69614064

Change-Id: I0c7ce7d3f344668587a75ec683343559a4caea99
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/22906
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/soc/intel/broadwell/Kconfig

@@ -140,10 +140,6 @@ config MRC_BIN_ADDRESS
 	hex
 	default 0xfffa0000
 
-config CACHE_MRC_SETTINGS
-	bool "Save cached MRC settings"
-	default y
-
 endif # HAVE_MRC
 
 config PRE_GRAPHICS_DELAY