drm/i915/pci: Remove force_probe requirement for DG1

Dunno why we still have .require_force_probe=1 on DG1 after
all this time. I'm not aware of any real problems with DG1,
so get rid of the force_probe requirement.

Generally the difficulty with DG1 is that it requires a
4GiB BAR for the local memory, and that's not something
that works on every system.

Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20250411144313.11660-3-ville.syrjala@linux.intel.com