usb: wusbcore: Add isoc transfer type enum and packet definitions

This patch adds transfer type enum and packet definitions for
WA_XFER_ISO_PACKET_INFO and WA_XFER_ISO_PACKET_STATUS packets.

It also changes instances of __attribute__((packed)) to __packed to make
checkpatch.pl happy.

Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>