payloads/external/GRUB2: Build only for supported architectures

GRUB2 doesn't support all architectures that coreboot supports.
Furthermore, coreboot's build script for GRUB2 doesn't support all of
these architectures.

Let the user select GRUB2 only when building for x86 and ARM, which are
known to work.

Change-Id: I5ef2020b2acb4cd008a57a2372734674f8b84a36
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-on: https://review.coreboot.org/23171
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

0 files changed, 0 insertions, 0 deletions