drm/nouveau: use nv_debug for NV_DEBUG, make DRM a separate subflag

It's really confusing for NV_DEBUG's printing to be controlled via
drm.debug while everything else is controlled via nouveau.debug. These
messages can be turned on with nouveau.debug=DRM=debug.
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_drm.c

@@ -33,6 +33,7 @@
 #include <core/client.h>
 #include <core/gpuobj.h>
 #include <core/class.h>
+#include <core/option.h>
 
 #include <engine/device.h>
 #include <engine/disp.h>
@@ -335,6 +336,7 @@ nouveau_drm_load(struct drm_device *dev, unsigned long flags)
 
 	dev->dev_private = drm;
 	drm->dev = dev;
+	nouveau_client(drm)->debug = nouveau_dbgopt(nouveau_debug, "DRM");
 
 	INIT_LIST_HEAD(&drm->clients);
 	spin_lock_init(&drm->tile.lock);

drivers/gpu/drm/nouveau/nouveau_drm.h

@@ -161,10 +161,7 @@ int nouveau_pmops_resume(struct device *);
 #define NV_ERROR(cli, fmt, args...) nv_error((cli), fmt, ##args)
 #define NV_WARN(cli, fmt, args...) nv_warn((cli), fmt, ##args)
 #define NV_INFO(cli, fmt, args...) nv_info((cli), fmt, ##args)
-#define NV_DEBUG(cli, fmt, args...) do {                                       \
-	if (drm_debug & DRM_UT_DRIVER)                                         \
-		nv_info((cli), fmt, ##args);                                   \
-} while (0)
+#define NV_DEBUG(cli, fmt, args...) nv_debug((cli), fmt, ##args)
 
 extern int nouveau_modeset;