drm/i915/fbc: replace frequent dev_priv->fbc.x with fbc->x

We say "dev_priv->fbc.something" way too many times in our code while
we could be saying just "fbc->something" with a previous declaration
of fbc. This has been bothering me for a while but I didn't want to
patch it since I wanted to fix the real problems first. But as I add
more code I keep thinking about it, especially since it makes the code
easier to read and it can make us fit 80 columns easier, so let's just
do the change now.

While at it, also rename from i915_fbc to intel_fbc because the whole
FBC code uses intel_fbc.

v2: Rebase after the work_fn changes.
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453406763-10400-1-git-send-email-paulo.r.zanoni@intel.com

drivers/gpu/drm/i915/i915_drv.h

@@ -900,7 +900,7 @@ enum fb_op_origin {
 	ORIGIN_DIRTYFB,
 };
 
-struct i915_fbc {
+struct intel_fbc {
 	/* This is always the inner lock when overlapping with struct_mutex and
 	 * it's the outer lock when overlapping with stolen_lock. */
 	struct mutex lock;
@@ -1781,7 +1781,7 @@ struct drm_i915_private {
 	u32 pipestat_irq_mask[I915_MAX_PIPES];
 
 	struct i915_hotplug hotplug;
-	struct i915_fbc fbc;
+	struct intel_fbc fbc;
 	struct i915_drrs drrs;
 	struct intel_opregion opregion;
 	struct intel_vbt_data vbt;