drm/i915/icl: Configure MG DP mode for HDMI ports too

The MG DP mode needs to be configured for Type C static/fixed/legacy
HDMI ports too, the same way as it's configured for Type C
static/fixed/legacy, fix this.

Bspec: 4232, 21735
Cc: Vandita Kulkarni <vandita.kulkarni@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Tested-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181102192656.4472-3-imre.deak@intel.com