amdgpu/pp: move PhwVega10_Magic to static const.

This isn't used outside this file.
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c

@@ -81,7 +81,7 @@ static const uint32_t channel_number[] = {1, 2, 0, 4, 0, 8, 0, 16, 2};
 static int vega10_force_clock_level(struct pp_hwmgr *hwmgr,
 		enum pp_clock_type type, uint32_t mask);
 
-const ULONG PhwVega10_Magic = (ULONG)(PHM_VIslands_Magic);
+static const ULONG PhwVega10_Magic = (ULONG)(PHM_VIslands_Magic);
 
 struct vega10_power_state *cast_phw_vega10_power_state(
 				  struct pp_hw_power_state *hw_ps)

drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.h

@@ -31,7 +31,6 @@
 #include "vega10_ppsmc.h"
 #include "vega10_powertune.h"
 
-extern const uint32_t PhwVega10_Magic;
 #define VEGA10_MAX_HARDWARE_POWERLEVELS 2
 
 #define WaterMarksExist  1