drm/i915: Enable fastboot across the board

drm/i915: Enable fastboot across the board

There's nothing magical about vlv+ platforms vs. fastboot.
If it works somewhere it should work everywhere, assuming
we've not missed any crucial state checks. That seems unlikely
on older platforms with less state to check anyway.

Just enable fastboot across the board, and the remove the
remnants of the optional stuff (we already removed the
modparam for fastboot anyway).

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240209183809.16887-6-ville.syrjala@linux.intel.com
Reviewed-by: Mika Kahola <mika.kahola@intel.com>