Fix the host mode ISOCHRONOUS transfer interval programming in the
SAF1761 OTG driver. Currently the driver logic is very simple and
double buffering the USB transactions is not done.  Also you need to
use an external USB high speed USB HUB for reliable FULL speed
outgoing ISOCHRONOUS traffic, because the internal one chokes on
so-called split transfers above 188 bytes.


git-svn-id: svn+ssh://svn.freebsd.org/base/head@274863 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f