drm/nv20: split PFB code out of nv10_fb.c

Most functions were quite different between NV10/NV20 already, and they're
about to get even more so.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/Makefile b/drivers/gpu/drm/nouveau/Makefile
index 9f27e3d..1a2ad7e 100644
--- a/drivers/gpu/drm/nouveau/Makefile
+++ b/drivers/gpu/drm/nouveau/Makefile
@@ -14,7 +14,8 @@
 	     nouveau_mm.o nouveau_vm.o nouveau_mxm.o nouveau_gpio.o \
              nv04_timer.o \
              nv04_mc.o nv40_mc.o nv50_mc.o \
-             nv04_fb.o nv10_fb.o nv30_fb.o nv40_fb.o nv50_fb.o nvc0_fb.o \
+             nv04_fb.o nv10_fb.o nv20_fb.o nv30_fb.o nv40_fb.o \
+             nv50_fb.o nvc0_fb.o \
              nv04_fifo.o nv10_fifo.o nv40_fifo.o nv50_fifo.o nvc0_fifo.o \
              nv04_graph.o nv10_graph.o nv20_graph.o \
              nv40_graph.o nv50_graph.o nvc0_graph.o \