usb: xhci: tegra: Firmware header is little endian

The XUSB firmware header is in little endian byte order, so make the
fields __le32 and __le16 instead of u32 and u16 to avoid warnings from
sparse when the fields are used with the endian-aware __le32_to_cpu()
and __le16_to_cpu() accessors, respectively.

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