drm/nouveau: implement module init functions in nouveau_drm.c

These currently just call the existing ones in nouveau_drv.c, but will be
extended in upcoming commits.  This needed to be separated from the current
code as there will be some header clashes until things are ported.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c
index fa22b28..7266902 100644
--- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
+++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
@@ -35,7 +35,7 @@
 
 #include "drmP.h"
 #include "nouveau_drv.h"
-#include "nouveau_drm.h"
+#include <nouveau_drm.h>
 #include "nouveau_reg.h"
 #include "nouveau_encoder.h"