switch compat_drm_getunique() to drm_ioctl_kernel()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
index 011205c..7299ba0 100644
--- a/drivers/gpu/drm/drm_internal.h
+++ b/drivers/gpu/drm/drm_internal.h
@@ -144,3 +144,4 @@
 }
 #endif
 drm_ioctl_t drm_version;
+drm_ioctl_t drm_getunique;