MFC r238274, r246752, r256720, r256721, r256722, r256955, r257409
 r257429, r257435, r257712, r257732, r257743, r257748, r257955
 r257957, r257958, r258082, r258641, r258643, r258732, r258733,
 r258840, r258919, r258921, r259029, r259030, r259031, r259032 and r259046:

- Add support for the MediaTek/Ralink RT5370/RT5372 chipset.
- Various minor USB WLAN fixes and improvements.

PR:     usb/182936