mb/google/poppy: Add variant callback for romstage GPIO configuration

This change adds variant callback to get GPIO configuration table in
romstage and configures these GPIOs before memory training is
performed.

BUG=b:111860510
BRANCH=poppy

Change-Id: I1eb51356fb3f4c0f4ff29b22dbcde6dbece303ad
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/27863
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
4 files changed