drm/amd/pm: Clean up errors in amd_powerplay.c

Fix the following errors reported by checkpatch:

ERROR: that open brace { should be on the previous line
ERROR: spaces required around that '||' (ctx:WxO)

Signed-off-by: Ran Sun <sunran001@208suo.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>