drm/i915/ddi: Set HDMI infoframes with pipe clocks enabled

On ICL for setting the HDMI infoframe the pipe clock needs to be
enabled, otherwise accessing the VIDEO_DIP_CTL register will hang the
machine.

Cc: Vandita Kulkarni <vandita.kulkarni@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180613170710.15080-5-imre.deak@intel.com