mac80211: rt2800-usb: enable "unknown" USB IDs

- should fix issue: https://forum.openwrt.org/viewtopic.php?id=57315


- enable support of more USB stick with rt28xx chipsets
- experimental: USB-IDs not in vendor linux driver
- experimental: "exact chipset is unknown"
- experimental: "enabling these devices may or may not work"

only compile tested

Signed-off-by: Dirk Neukirchen <dirkneukirchen@web.de>

SVN-Revision: 46882