drm/amd: drop use of drmP.h in powerplay/

Delete the only include of drmP.h in powerplay/.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: "David (ChunMing) Zhou" <David1.Zhou@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190609220757.10862-8-sam@ravnborg.org

drivers/gpu/drm/amd/powerplay/amdgpu_smu.c

@@ -20,9 +20,9 @@
  * OTHER DEALINGS IN THE SOFTWARE.
  */
 
-#include "pp_debug.h"
 #include <linux/firmware.h>
-#include <drm/drmP.h>
+
+#include "pp_debug.h"
 #include "amdgpu.h"
 #include "amdgpu_smu.h"
 #include "soc15_common.h"