drm/i915: remove duplicate typedef for intel_wakeref_t

Fix the duplicate typedef for intel_wakeref_t leading to Clang build
issues. While at it, actually make the intel_runtime_pm.h header
self-contained, which was claimed in the commit being fixed.
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
References: http://mid.mail-archive.com/20190521183850.GA9157@archlinux-epyc
References: https://travis-ci.com/ClangBuiltLinux/continuous-integration/jobs/201754420#L2435
Fixes: 0d5adc5f ("drm/i915: extract intel_runtime_pm.h from intel_drv.h")
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190522103505.2082-1-jani.nikula@intel.com

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

@@ -55,6 +55,7 @@ header_test := \
 	intel_pm.h \
 	intel_psr.h \
 	intel_quirks.h \
+	intel_runtime_pm.h \
 	intel_sdvo.h \
 	intel_sideband.h \
 	intel_sprite.h \

drivers/gpu/drm/i915/intel_runtime_pm.h

@@ -6,12 +6,14 @@
 #ifndef __INTEL_RUNTIME_PM_H__
 #define __INTEL_RUNTIME_PM_H__
 
-#include <linux/stackdepot.h>
 #include <linux/types.h>
 
-struct drm_i915_private;
+#include "intel_display.h"
+#include "intel_wakeref.h"
 
-typedef depot_stack_handle_t intel_wakeref_t;
+struct drm_i915_private;
+struct drm_printer;
+struct intel_encoder;
 
 enum i915_drm_suspend_mode {
 	I915_DRM_SUSPEND_IDLE,