vboot2: Store depthcharge graphic assets only in RO

These files aren't updated (or updatable), and as such don't need to be
copied to the RW sections.

Change-Id: Ie78936792ad651fbf8500fc7e34f0899e33a904c
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: https://review.coreboot.org/13633
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
1 file changed