drm/amd/pm: fix Navi1x runtime resume failure V2

The RLC was put into a wrong state on runtime suspend. Thus the RLC
autoload will fail on the succeeding runtime resume. By adding an
intermediate PPSMC_MSG_PrepareMp1ForUnload(some GC hard reset involved,
designed for PnP), we can bring RLC back into the desired state.

V2: integrate INTERRUPTS_ENABLED flag clearing into current
    mp1 state set routines

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Guchun Chen <guchun.chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>