drm/amdgpu: fix memory clock can't switch on CI.

if we set only lowest mclk level enabled,
when we enable uvd dpm during boot time,
mclk will be fixed in the lowest level.
the mclk switch will fail if try to enable
other level of mclk at this time.
so set all mclk levels enabled.

Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>