drm/amd/pm: revise the driver reloading fix for SMU 13.0.0 and 13.0.7

The current approach breaks S3/S4 as asic reset is needed for them.
And putting SMU out of service(via SMU_MSG_PrepareMp1ForUnload) will make
that(asic reset) failed. Considering with current designs, there is
actually also asic reset involved on driver reloading. That can make
asic back to a clean state. So, the SMU_MSG_PrepareMp1ForUnload operation
will be not so necessary. Thus we will just drop the SMU_MSG_PrepareMp1ForUnload
operation. We may revise the whole driver reloading sequences when there
is a better design.

Fixes: 72aeb6ee ("drm/amd/pm: fix driver reload SMC firmware fail issue for smu13")
Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>