drm/i915: Replace manual lvds and sdvo/hdmi counting with intel_crtc_has_type()

Since we now have the output_types bitmaks in the crtc state, there's no
need to iterate through all the encoders to see if an LVDS or SDVO/HDMI
encoder might be present.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466621833-5054-6-git-send-email-ville.syrjala@linux.intel.com