guest vm gets 0xffffffff when reading RCC_DEV0_EPF0_STRAP0,
as a consequence, the rev_id and external_rev_id are wrong.
workaround it by hardcoding the rev_id to 0, which is the default value.
v2. add comment in the code
Signed-off-by: Tiecheng Zhou <Tiecheng.Zhou@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
