build system: use strip_quotes on cbfs-files

If they come from the build system, file names might be guarded in
quotes, which confuses make. Drop them here.

Change-Id: Ice0d3c4bc2c45a3f121a85e1b9f5f6420c5761d5
Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com>
Reviewed-on: http://review.coreboot.org/1866
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
1 file changed