[why] recent VBIOS dce_infotable reference clock change caused a I2c regression. instead of relying on vbios, let's get it from HW directly. Signed-off-by: Charlene Liu <Charlene.Liu@amd.com> Reviewed-by: Chris Park <Chris.Park@amd.com> Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com> Acked-by: Bindu Ramamurthy <bindu.r@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>