vboot: provide RW region device support

Explicitly provide a RW view of an vboot FMAP region. This is
required for platforms which have separate implementations of
a RO boot device and a RW boot device.

BUG=chrome-os-partner:56151

Change-Id: If8bf2e1c7ca9bff536fc5c578fe0cf92ccbd2ebc
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/16205
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins)
2 files changed