(split) Use relaxed (write-only) memory barriers when writing some of queue index
registers (for now on ISP2400+).  We never read those registers back and
AFAIK their semantics does not require any immediate reaction on write.
(split) Add support for the MediaTek/Ralink RT5370/RT5372 chipset.

Tested with the TP-Link TL-WN727N (RT5370) and the D-Link DWA-140 (RT5372)
on i386/amd64/arm with WPA.
(split) Remove r257748 by accident.
(split) Use the real product name for Edimax rsu(4) id.
(split) - Use bit twiddling macro to set IEEE80211_MODE_11A
- On the RT3572 chipset, there's no need to configure BBP register 86
(split) Remove a couple of unused macros.
(split) Merge branch 'CURRENT' (commit 'cf61e85a')

Conflicts:
	sys/dev/usb/wlan/if_run.c