drm/i915: extract intel_csr.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.

v2: Add function argument names to fix checkpatch warning
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/44ceebca0206de9c40dc6794b660d84b8994f700.1554461791.git.jani.nikula@intel.com

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

@@ -12,6 +12,7 @@ header_test := \
 	intel_connector.h \
 	intel_context_types.h \
 	intel_crt.h \
+	intel_csr.h \
 	intel_ddi.h \
 	intel_engine_types.h \
 	intel_frontbuffer.h \

drivers/gpu/drm/i915/i915_drv.c

@@ -54,6 +54,7 @@
 #include "i915_trace.h"
 #include "i915_vgpu.h"
 #include "intel_audio.h"
+#include "intel_csr.h"
 #include "intel_drv.h"
 #include "intel_uc.h"
 #include "intel_workarounds.h"

drivers/gpu/drm/i915/intel_csr.c

@@ -21,9 +21,12 @@
  * IN THE SOFTWARE.
  *
  */
+
 #include <linux/firmware.h>
+
 #include "i915_drv.h"
 #include "i915_reg.h"
+#include "intel_csr.h"
 
 /**
  * DOC: csr support for dmc

drivers/gpu/drm/i915/intel_csr.h

+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#ifndef __INTEL_CSR_H__
+#define __INTEL_CSR_H__
+
+struct drm_i915_private;
+
+void intel_csr_ucode_init(struct drm_i915_private *i915);
+void intel_csr_load_program(struct drm_i915_private *i915);
+void intel_csr_ucode_fini(struct drm_i915_private *i915);
+void intel_csr_ucode_suspend(struct drm_i915_private *i915);
+void intel_csr_ucode_resume(struct drm_i915_private *i915);
+
+#endif /* __INTEL_CSR_H__ */

drivers/gpu/drm/i915/intel_drv.h

@@ -1846,13 +1846,6 @@ unsigned int i9xx_plane_max_stride(struct intel_plane *plane,
 				   u32 pixel_format, u64 modifier,
 				   unsigned int rotation);
 
-/* intel_csr.c */
-void intel_csr_ucode_init(struct drm_i915_private *);
-void intel_csr_load_program(struct drm_i915_private *);
-void intel_csr_ucode_fini(struct drm_i915_private *);
-void intel_csr_ucode_suspend(struct drm_i915_private *);
-void intel_csr_ucode_resume(struct drm_i915_private *);
-
 /* intel_dp.c */
 struct link_config_limits {
 	int min_clock, max_clock;

drivers/gpu/drm/i915/intel_runtime_pm.c

@@ -33,6 +33,7 @@
 
 #include "i915_drv.h"
 #include "intel_crt.h"
+#include "intel_csr.h"
 #include "intel_drv.h"
 
 /**