payloads/seabios: Add "git revision" to the SeaBIOS version menu

Add an option to specify a git revision from which to build SeaBIOS.

Change-Id: Ifbf3b82e784f79395ab7cd07c5804f72928d7640
Signed-off-by: Antonello Dettori <dev@dettori.io>
Reviewed-on: https://review.coreboot.org/13937
Reviewed-by: Alexander Couzens <lynxis@fe80.eu>
Tested-by: build bot (Jenkins)
3 files changed