usb: Add USB3.1 SuperSpeedPlus Isoc Endpoint Companion descriptor

USB3.1 specifies a SuperSpeedPlus Isoc endpoint companion descriptor
which is returned as part of the devices complete configuration
descriptor.

It contains number of bytes per service interval which is needed when
reserving bus time in the schedule for transfers over 48K bytes per
service interval.

If bmAttributes bit 7 is set in the old SuperSpeed Endpoint Companion
descriptor, it will be ollowed by the new SuperSpeedPlus Isoc Endpoint
Companion descriptor.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>