drm/i915/mtl: Initial DDI port setup

Initialization sequences and C10 phy are in place to be able to enable
the first 2 ports of MTL. The other ports use C20 phy that still need
to be properly added. Enable the first ports for now, keeping a TODO
comment about the others.

Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Signed-off-by: Clint Taylor <clinton.a.taylor@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230413212443.1504245-10-radhakrishna.sripada@intel.com