drm/i915/icl: Add TypeC ports only if VBT is present

drm/i915/icl: Add TypeC ports only if VBT is present

We can't safely probe Type C ports, whether they are a legacy or a
USB/Thunderbolt DP Alternate Type C port. This would require performing
the TypeC connect sequence - as described by the specification - but
that may have unwanted side-effects. These side-effects include at least
- without completeness - timeouts during AUX power well enabling and
subsequent PLL enabling errors.

To safely identify these ports we really need VBT, which has the proper
flag for this (ddi_vbt_port_info::supports_typec_usb, supports_tbt).
Based on the above disable Type C ports if we can't load VBT for some
reason.

v2:
- Notice that we disable TypeC ports completely and simplify accordingly
  (Jose).
- Add code comment explaining why we disabled the ports. (Jani)

Cc: Jani Nikula <[email protected]>
Cc: Paulo Zanoni <[email protected]>
Cc: Jose Roberto de Souza <[email protected]>
Cc: Ville Syrjälä <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Signed-off-by: Imre Deak <[email protected]>
Reviewed-by: José Roberto de Souza <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]