Lenovo X250 has a PnpID of LEN0046, but it does not have the top software
button requirement.

For the record, Lenovo T450s and W541 have a PnpID of LEN200f and LEN004a,
so they are not on the top software button list.
Signed-off-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: NDaniel Martin <consume.noise@gmail.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>