usb: hub: Fix usb_get_port_status() for big-endian platforms

Add missing endianness conversions to usb_get_port_status(). This
(amongst others) is necessary to enable the use of USB 3 hubs on
big-endian platforms like MIPS Octeon.

Signed-off-by: Aaron Williams <awilliams@marvell.com>
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Chandrakala Chavva <cchavva@marvell.com>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Marek Vasut <marex@denx.de>