drm/virtgpu: drop use of drmP.h

Drop use of the deprecated drmP.h header file.
Fix fallout by adding missing include files.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Emil Velikov <emil.velikov@collabora.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: virtualization@lists.linux-foundation.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190630061922.7254-28-sam@ravnborg.org
diff --git a/drivers/gpu/drm/virtio/virtgpu_prime.c b/drivers/gpu/drm/virtio/virtgpu_prime.c
index 8fbf71b..8b3b2ca 100644
--- a/drivers/gpu/drm/virtio/virtgpu_prime.c
+++ b/drivers/gpu/drm/virtio/virtgpu_prime.c
@@ -22,6 +22,8 @@
  * Authors: Andreas Pokorny
  */
 
+#include <drm/drm_prime.h>
+
 #include "virtgpu_drv.h"
 
 /* Empty Implementations as there should not be any other driver for a virtual