drm/i915: make intel_dpll_mgr.h self-contained

And ensure it stays that way.
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/8e759b36dee10c20aa06e4d34d36cda6a2a02323.1556540889.git.jani.nikula@intel.com

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

@@ -22,6 +22,7 @@ header_test := \
 	intel_csr.h \
 	intel_ddi.h \
 	intel_dp.h \
+	intel_dpll_mgr.h \
 	intel_drv.h \
 	intel_dvo.h \
 	intel_dvo_dev.h \

drivers/gpu/drm/i915/intel_dpll_mgr.c

@@ -21,6 +21,7 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+#include "intel_dpll_mgr.h"
 #include "intel_drv.h"
 
 /**

drivers/gpu/drm/i915/intel_dpll_mgr.h

@@ -25,6 +25,10 @@
 #ifndef _INTEL_DPLL_MGR_H_
 #define _INTEL_DPLL_MGR_H_
 
+#include <linux/types.h>
+
+#include "intel_display.h"
+
 /*FIXME: Move this to a more appropriate place. */
 #define abs_diff(a, b) ({			\
 	typeof(a) __a = (a);			\
@@ -32,13 +36,13 @@
 	(void) (&__a == &__b);			\
 	__a > __b ? (__a - __b) : (__b - __a); })
 
+struct drm_atomic_state;
+struct drm_device;
 struct drm_i915_private;
 struct intel_crtc;
 struct intel_crtc_state;
 struct intel_encoder;
-
 struct intel_shared_dpll;
-struct intel_dpll_mgr;
 
 /**
  * enum intel_dpll_id - possible DPLL ids