tests/i915/module_load: fix resize-bar on DG1

DG1, as expected only has a fixed sized bar, so attempting to force the
BAR size should fail. Update the test to account for such devices, and
perform a skip, instead of failing.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6458


Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Nirmoy Das <nirmoy.das@intel.com>
Tested-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>