drm/i915/tgl: Add additional ports for Tiger Lake

There are 2 new additional typeC ports in Tiger Lake and PORT-C is now a
combophy port. This results in 6 typeC ports and 3 combophy ports.
These 6 TC ports can be DP alternate mode, DP over thunderbolt, native
DP on legacy DP connector or native HDMI on legacy connector.

v2: Rebase on new modular FIA code (Lucas)
v3: Also add new port in port_identifier(), even though it can't
    possibly be used there (requested by José)
v4: Add conversion port->tc_port in helper function after introction of
    phy namespace (Lucas)

Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190711173115.28296-13-lucas.demarchi@intel.com