drm/amd/pm: Clean up errors in vega12_hwmgr.h

Fix the following errors reported by checkpatch:

ERROR: open brace '{' following enum go on the same line
Signed-off-by: Ran Sun <sunran001@208suo.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega12_hwmgr.h

@@ -38,8 +38,7 @@
 #define VG12_PSUEDO_NUM_DCEFCLK_DPM_LEVELS  8
 #define VG12_PSUEDO_NUM_UCLK_DPM_LEVELS     4
 
-enum
-{
+enum {
 	GNLD_DPM_PREFETCHER = 0,
 	GNLD_DPM_GFXCLK,
 	GNLD_DPM_UCLK,