drm/amd/pm: do not use ixFEATURE_STATUS for checking smc running

[ Upstream commit 786436b453001dafe81025389f96bf9dac1e9690 ]

This reverts commit f87812284172a9809820d10143b573d833cd3f75 ("drm/amdgpu:
Fix bug where DPM is not enabled after hibernate and resume").
It was intended to fix Hawaii S4(hibernation) issue but break S3. As
ixFEATURE_STATUS is filled with garbage data on resume which can be
only cleared by reloading smc firmware(but that will involve many
changes). So, we will revert this S4 fix and seek a new way.

Signed-off-by: Evan Quan <evan.quan@amd.com>
Tested-by: Sandeep Raghuraman <sandy.8925@gmail.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>