drm/i915/bios: start using the intel_bios_encoder_data directly

Start using struct intel_bios_encoder_data directly. We'll start
sanitizing the child device data directly as well, instead of the cached
data in ddi_port_info[]. The one downside here is having to store a
non-const pointer back to intel_bios_encoder_data.

Eventually we'll be able to have a direct pointer from encoder to
intel_bios_encoder_data, removing the need to go through the
ddi_port_info[] array altogether. And we'll be able to remove all the
cached data in ddi_port_info[].

v2:
- Remove supports_dp and supports_edp from ddi_port_info too
- Add devdata != NULL check in intel_bios_is_port_edp()

Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com> # v1
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/061df32a012ff640060920fcd730fb23f8717ee8.1615998927.git.jani.nikula@intel.com