drm/amdgpu/powerplay: Modify SMC message name for setting power profile mode

I consulted Cai Land(Chuntian.Cai@amd.com), he told me corresponding smc
message name to fSMC_MSG_SetWorkloadMask() is
"PPSMC_MSG_ActiveProcessNotify" in firmware code of Renoir.

Strange though it may seem, but it's a fact.

Signed-off-by: chen gong <curry.gong@amd.com>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org