drm/i915: Configure eDP PLL freq from ironlake_edp_pll_on()

drm/i915: Configure eDP PLL freq from ironlake_edp_pll_on()

ironlake_set_pll_cpu_edp() only gets called just before
ironlake_edp_pll_on(), so just pull the code into ironlake_edp_pll_on().

Also toss in a debug print into ironlake_edp_pll_off() to match the one
we have in ironlake_edp_pll_on().

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446146763-31821-15-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>