drm/i915: Drop a useless forward declararion

ilk_pfit_enable() is defined before the first use. No need
for a forwared declaration.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230418175528.13117-9-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>

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

@@ -123,7 +123,6 @@ static void intel_set_transcoder_timings(const struct intel_crtc_state *crtc_sta
 static void intel_set_pipe_src_size(const struct intel_crtc_state *crtc_state);
 static void hsw_set_transconf(const struct intel_crtc_state *crtc_state);
 static void bdw_set_pipe_misc(const struct intel_crtc_state *crtc_state);
-static void ilk_pfit_enable(const struct intel_crtc_state *crtc_state);
 
 /* returns HPLL frequency in kHz */
 int vlv_get_hpll_vco(struct drm_i915_private *dev_priv)