USB: asix - Fix endian issues in asix_tx_fixup()

The attached patch fixes endian issues in asix_tx_fixup() that prevented
AX88772 and AX88178 devices from working on big-endian systems.  With
the attached patch, all three chips are reported to work on big endian.

Signed-off-by: David Hollis <dhollis@davehollis.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>