drm/i915/dpll: hide struct intel_dpll_funcs

The struct is only needed in intel_dpll.c, move it there.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/fedb27386cbad2b162d83a706273dd8ad9e8eed2.1643896905.git.jani.nikula@intel.com

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

@@ -16,6 +16,10 @@
 #include "intel_snps_phy.h"
 #include "vlv_sideband.h"
 
+struct intel_dpll_funcs {
+	int (*crtc_compute_clock)(struct intel_crtc_state *crtc_state);
+};
+
 struct intel_limit {
 	struct {
 		int min, max;

drivers/gpu/drm/i915/i915_drv.h

@@ -119,6 +119,7 @@ struct intel_color_funcs;
 struct intel_connector;
 struct intel_crtc;
 struct intel_dp;
+struct intel_dpll_funcs;
 struct intel_encoder;
 struct intel_fbdev;
 struct intel_fdi_funcs;
@@ -323,10 +324,6 @@ struct drm_i915_wm_disp_funcs {
 	int (*compute_global_watermarks)(struct intel_atomic_state *state);
 };
 
-struct intel_dpll_funcs {
-	int (*crtc_compute_clock)(struct intel_crtc_state *crtc_state);
-};
-
 struct drm_i915_display_funcs {
 	/* Returns the active state of the crtc, and if the crtc is active,
 	 * fills out the pipe-config with the hw state. */