drm/nouveau: rename nvd0_display to nv50_display to reflect reality since merge

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/Makefile b/drivers/gpu/drm/nouveau/Makefile
index b834a34..a96af78 100644
--- a/drivers/gpu/drm/nouveau/Makefile
+++ b/drivers/gpu/drm/nouveau/Makefile
@@ -201,7 +201,7 @@
 nouveau-y += nv04_crtc.o nv04_display.o nv04_cursor.o
 
 # drm/kms/nv50-
-nouveau-y += nvd0_display.o
+nouveau-y += nv50_display.o
 
 # drm/pm
 nouveau-y += nouveau_pm.o nouveau_volt.o nouveau_perf.o