drm: Add acquire ctx parameter to ->set_config

Surprisingly a lot of legacy drivers roll their own, for
runtime pm and because vmwgfx.

Also make nouveau's set_config static while at it.

Cc: Sinclair Yeh <syeh@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170322215058.8671-19-daniel.vetter@ffwll.ch

drivers/gpu/drm/drm_atomic_helper.c

@@ -2265,6 +2265,7 @@ static int update_output_state(struct drm_atomic_state *state,
 /**
  * drm_atomic_helper_set_config - set a new config from userspace
  * @set: mode set configuration
+ * @ctx: lock acquisition context
  *
  * Provides a default crtc set_config handler using the atomic driver interface.
  *
@@ -2277,7 +2278,8 @@ static int update_output_state(struct drm_atomic_state *state,
  * Returns:
  * Returns 0 on success, negative errno numbers on failure.
  */
-int drm_atomic_helper_set_config(struct drm_mode_set *set)
+int drm_atomic_helper_set_config(struct drm_mode_set *set,
+				 struct drm_modeset_acquire_ctx *ctx)
 {
 	struct drm_atomic_state *state;
 	struct drm_crtc *crtc = set->crtc;