drm/i915/cdclk: turn around i915_drv.h and intel_cdclk.h dependency

intel_cdclk.h only needs i915_drv.h for struct intel_cdclk_config. Move
the definition to intel_cdclk.h and turn the includes around to avoid
including i915_drv.h from other headers.

The intel cdclk state macros in intel_cdclk.h still reference struct
drm_i915_private, but as macros they don't strictly require the
definition until they are used.

v2: Expand on the commit message wrt cdclk state macros
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211213114106.296017-1-jani.nikula@intel.com

drivers/gpu/drm/i915/display/intel_atomic.c

@@ -34,6 +34,7 @@
 #include <drm/drm_fourcc.h>
 #include <drm/drm_plane_helper.h>
 
+#include "i915_drv.h"
 #include "intel_atomic.h"
 #include "intel_cdclk.h"
 #include "intel_display_types.h"

drivers/gpu/drm/i915/display/intel_cdclk.h

@@ -8,7 +8,6 @@
 
 #include <linux/types.h>
 
-#include "i915_drv.h"
 #include "intel_display.h"
 #include "intel_global_state.h"
 
@@ -16,6 +15,11 @@ struct drm_i915_private;
 struct intel_atomic_state;
 struct intel_crtc_state;
 
+struct intel_cdclk_config {
+	unsigned int cdclk, vco, ref, bypass;
+	u8 voltage_level;
+};
+
 struct intel_cdclk_state {
 	struct intel_global_state base;
 

drivers/gpu/drm/i915/i915_drv.h

@@ -65,6 +65,7 @@
 #include "i915_utils.h"
 
 #include "display/intel_bios.h"
+#include "display/intel_cdclk.h"
 #include "display/intel_display.h"
 #include "display/intel_display_power.h"
 #include "display/intel_dmc.h"
@@ -627,11 +628,6 @@ struct i915_virtual_gpu {
 	u32 caps;
 };
 
-struct intel_cdclk_config {
-	unsigned int cdclk, vco, ref, bypass;
-	u8 voltage_level;
-};
-
 struct i915_selftest_stash {
 	atomic_t counter;
 	struct ida mock_region_instances;