drm/i915/bios: Throw out the !has_ddi_port_info() codepaths

drm/i915/bios: Throw out the !has_ddi_port_info() codepaths

Now that we parse the DDI port info from the VBT on all g4x+ platforms
we can throw out all the old codepaths in intel_bios_is_port_present(),
intel_bios_is_port_edp() and intel_bios_is_port_dp_dual_mode(). None
of these should be called on pre-g4x platforms.

For good measure throw in a WARN into intel_bios_is_port_present()
should someone get the urge to call it on older platforms. The
other two functions are specific to HDMI and DP so should not need
any protection as those encoder types don't even exist on older
platforms.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211217155403.31477-5-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>