commonlib: Add common cbfs parsing logic to coreboot and cbfstool.

To continue sharing more code between the tools and
coreboot proper provide cbfs parsing logic in commonlib.
A cbfs_for_each_file() function was added to allow
one to act on each file found within a cbfs. cbfs_locate()
was updated to use that logic.

BUG=chrome-os-partner:48412
BUG=chromium:445938
BRANCH=None
TEST=Utilized and booted on glados.

Change-Id: I1f23841583e78dc3686f106de9eafe1adbef8c9f
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/12783
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/commonlib/Makefile.inc

@@ -10,3 +10,9 @@ ramstage-y += region.c
 smm-y += region.c
 
 ramstage-$(CONFIG_PLATFORM_USES_FSP1_1) += fsp1_1_relocate.c
+
+bootblock-y += cbfs.c
+verstage-y += cbfs.c
+romstage-y += cbfs.c
+ramstage-y += cbfs.c
+smm-y += cbfs.c