(split) Rename 'vm_interrupt_hostcpu()' to 'vcpu_notify_event()' because the function
has outgrown its original name. Originally this function simply sent an IPI
to the host cpu that a vcpu was executing on but now it does a lot more than
just that.

Reviewed by:	grehan@
(split) Fix external compiler warning(s). Avoid pointer dereferencing.
(split) Fix what looks like a typo after r258732.
(split) Remove daft KASSERT.
(split) Cosmetic changes.
(split) Replace the magic numbers with something more readable.
(split) Add support for the MediaTek/Ralink RT5572 chipset.
Committed over the TP-LINK TL-WDN3200 (RT5572) on amd64 with WPA.

While here, add my copyright.
(split) Fix compilation when the "USB_DEBUG" option is set.
(split) Merge branch 'CURRENT' (commit 'a5fb9c53')

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