We need to get the silicon revision id before we parse
the firmware in order to load the correct gpu info firmware
for raven2 variants.

Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1103Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>