drm/i915/display: remove PORT_F workaround for CNL

Explicit support for CNL is being removed from the driver as it's not
expected to work. Remove the workaround for PORT_F from
display/intel_bios.c so we can also remove the generic DISPLAY_VER == 10
calls to intel_ddi_init(): the only platform with that display version
is already handled separately (GLK).

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/20210728215946.1573015-2-lucas.demarchi@intel.com