drm/i915: Get rid of crtc->config from icl_pll_to_ddi_pll_sel

Pass the full state to intel_ddi_clk_select, so we can pass it
to icl_pll_to_ddi_pll_sel instead of passign the crtc and having
to dereference crtc->config

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181004094604.2646-10-maarten.lankhorst@linux.intel.com