drm/i915: extract intel_quirks.h from intel_drv.h

It used to be handy that we only had a couple of headers, but over time
intel_drv.h has become unwieldy. Extract declarations to a separate
header file corresponding to the implementation module, clarifying the
modularity of the driver.

Ensure the new header is self-contained, and do so with minimal further
includes, using forward declarations as needed. Include the new header
only where needed, and sort the modified include directives while at it
and as needed.

No functional changes.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1e2fb90dcce2063b1c464dc64aa8fa6005b62bc6.1556540890.git.jani.nikula@intel.com

drivers/gpu/drm/i915/Makefile.header-test

@@ -43,8 +43,9 @@ header_test := \
 	intel_pipe_crc.h \
 	intel_pm.h \
 	intel_psr.h \
-	intel_sideband.h \
+	intel_quirks.h \
 	intel_sdvo.h \
+	intel_sideband.h \
 	intel_sprite.h \
 	intel_tv.h \
 	intel_uncore.h \

drivers/gpu/drm/i915/intel_display.c

@@ -67,6 +67,7 @@
 #include "intel_pipe_crc.h"
 #include "intel_pm.h"
 #include "intel_psr.h"
+#include "intel_quirks.h"
 #include "intel_sdvo.h"
 #include "intel_sideband.h"
 #include "intel_sprite.h"

drivers/gpu/drm/i915/intel_drv.h

@@ -1789,9 +1789,6 @@ int intel_overlay_attrs_ioctl(struct drm_device *dev, void *data,
 			      struct drm_file *file_priv);
 void intel_overlay_reset(struct drm_i915_private *dev_priv);
 
-/* intel_quirks.c */
-void intel_init_quirks(struct drm_i915_private *dev_priv);
-
 /* intel_runtime_pm.c */
 void intel_runtime_pm_init_early(struct drm_i915_private *dev_priv);
 int intel_power_domains_init(struct drm_i915_private *);

drivers/gpu/drm/i915/intel_quirks.c

@@ -6,6 +6,7 @@
 #include <linux/dmi.h>
 
 #include "intel_drv.h"
+#include "intel_quirks.h"
 
 /*
  * Some machines (Lenovo U160) do not work with SSC on LVDS for some reason

drivers/gpu/drm/i915/intel_quirks.h

+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#ifndef __INTEL_QUIRKS_H__
+#define __INTEL_QUIRKS_H__
+
+struct drm_i915_private;
+
+void intel_init_quirks(struct drm_i915_private *dev_priv);
+
+#endif /* __INTEL_QUIRKS_H__ */