drm/i915: digital_port_connected sort platforms newer-to-older

Just sorting this "if" block from newer to older platform.

The main difference here is the addition of a
missing case with return false that should never occur.
And if it occurs it is better than to raise a warn
than use the icl one.

The gen >= 11 was already present in the previous logic,
although hidden.

So, in summary no real functional change.

Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181022171526.15641-3-rodrigo.vivi@intel.com