src/lib: Enable display of cbmem during romstage and postcar

Enable the display of cbmem during romstage and postcar.  Add a Kconfig
value to prevent coreboot images from increasing in size when this
feature is not in use.

TEST=Build and run on Galileo Gen2

Change-Id: Ib70ad517ebf7d37a7f46ba503b4432c7c04d7ded
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: https://review.coreboot.org/15842
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/Kconfig

@@ -209,6 +209,12 @@ config NO_XIP_EARLY_STAGES
 config EARLY_CBMEM_INIT
 	def_bool !LATE_CBMEM_INIT
 
+config EARLY_CBMEM_LIST
+	bool
+	default n
+	help
+	  Enable display of CBMEM during romstage and postcar.
+
 config COLLECT_TIMESTAMPS
 	bool "Create a table of timestamps collected during boot"
 	default n