drm/i915: Use g4x_get_aux_clock_divider() for VLV/CHV

With the hrawclk frequency cached in dev_priv, we can simply use
g4x_get_aux_clock_divider() for VLV/CHV.

v2: Rebase due to IS_VALLYVIEW vs. IS_CHERRYVIEW split

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1456932138-14004-4-git-send-email-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/intel_dp.c

@@ -720,11 +720,6 @@ static uint32_t hsw_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
 	}
 }
 
-static uint32_t vlv_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
-{
-	return index ? 0 : 100;
-}
-
 static uint32_t skl_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
 {
 	/*
@@ -5859,8 +5854,6 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
 	/* intel_dp vfuncs */
 	if (INTEL_INFO(dev)->gen >= 9)
 		intel_dp->get_aux_clock_divider = skl_get_aux_clock_divider;
-	else if (IS_VALLEYVIEW(dev) || IS_CHERRYVIEW(dev))
-		intel_dp->get_aux_clock_divider = vlv_get_aux_clock_divider;
 	else if (IS_HASWELL(dev) || IS_BROADWELL(dev))
 		intel_dp->get_aux_clock_divider = hsw_get_aux_clock_divider;
 	else if (HAS_PCH_SPLIT(dev))