nouveau: delete nouveau_class.h, move nv50 regs to nv50_reg.h

nv50 should switch to rules-ng-ng too at some point.

The classic Mesa Nouveau driver also includes a copy of nouveau_class.h,
and should convert to rules-ng-ng too and remove it.

src/gallium/drivers/nouveau/nouveau_winsys.h

@@ -6,7 +6,6 @@
 
 #include "nouveau/nouveau_bo.h"
 #include "nouveau/nouveau_channel.h"
-#include "nouveau/nouveau_class.h"
 #include "nouveau/nouveau_device.h"
 #include "nouveau/nouveau_grobj.h"
 #include "nouveau/nouveau_notifier.h"

src/gallium/drivers/nv50/nv50_context.h

@@ -16,6 +16,7 @@
 #include "nouveau/nouveau_winsys.h"
 #include "nouveau/nouveau_gldefs.h"
 #include "nouveau/nouveau_stateobj.h"
+#include "nv50_reg.h"
 
 #include "nv50_screen.h"
 #include "nv50_program.h"