net: usb: cdc-ncm: check for filtering capability

If the decice does not support filtering, filtering
must not be used and all packets delivered for the
upper layers to sort.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Link: https://patch.msgid.link/20250717120649.2090929-1-oneukum@suse.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>