drm/i915/display/mtl: Fill port width in DDI_BUF_/TRANS_DDI_FUNC_/PORT_BUF_CTL for HDMI

MTL requires the PORT_CTL_WIDTH, TRANS_DDI_FUNC_CTL and DDI_BUF_CTL
to be filled with 4 lanes for TMDS mode.
This patch enables D2D link and fills PORT_WIDTH in appropriate
registers.

v2:
  - Added fixes from Clint's Add HDMI implementation changes.
  - Modified commit message.
v3:
  - Use TRANS_DDI_PORT_WIDTH() instead of DDI_PORT_WIDTH() for the value
    of TRANS_DDI_FUNC_CTL_*. (Gustavo)

Cc: Taylor, Clinton A <clinton.a.taylor@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230413212443.1504245-9-radhakrishna.sripada@intel.com