drm/i915: split out vlv/chv specific suspend/resume code

i915_drv.c is a fairly big file, and having very specific vlv/chv
suspend/resume code in it is a distraction. Split it out to a new
vlv_suspend.[ch] file.
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/20200212144058.5686-1-jani.nikula@intel.com

drivers/gpu/drm/i915/Makefile

@@ -53,7 +53,8 @@ i915-y += i915_drv.o \
 	  intel_runtime_pm.o \
 	  intel_sideband.o \
 	  intel_uncore.o \
-	  intel_wakeref.o
+	  intel_wakeref.o \
+	  vlv_suspend.o
 
 # core library code
 i915-y += \

drivers/gpu/drm/i915/i915_drv.h

@@ -1755,8 +1755,6 @@ void i915_driver_remove(struct drm_i915_private *i915);
 int i915_resume_switcheroo(struct drm_i915_private *i915);
 int i915_suspend_switcheroo(struct drm_i915_private *i915, pm_message_t state);
 
-int vlv_force_gfx_clock(struct drm_i915_private *dev_priv, bool on);
-
 static inline bool intel_gvt_active(struct drm_i915_private *dev_priv)
 {
 	return dev_priv->gvt;

drivers/gpu/drm/i915/vlv_suspend.h

+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2020 Intel Corporation
+ */
+
+#ifndef __VLV_SUSPEND_H__
+#define __VLV_SUSPEND_H__
+
+#include <linux/types.h>
+
+struct drm_i915_private;
+
+int vlv_suspend_init(struct drm_i915_private *i915);
+void vlv_suspend_cleanup(struct drm_i915_private *i915);
+int vlv_suspend_complete(struct drm_i915_private *i915);
+int vlv_resume_prepare(struct drm_i915_private *i915, bool rpm_resume);
+
+#endif /* __VLV_SUSPEND_H__ */