drm/amd/powerplay: fix vce cg logic error on CZ/St.

drm/amd/powerplay: fix vce cg logic error on CZ/St.

[ Upstream commit 3731d12dce83d47b357753ffc450ce03f1b49688 ]

can fix Bug 191281: vce ib test failed.

when vce idle, set vce clock gate, so the clock
in vce domain will be disabled.
when need to encode, disable vce clock gate,
enable the clocks to vce engine.

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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>