cxgb4: Fix endianness issue in t4_fwcache()

Do not put host-endian 0 or 1 into big endian feild.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>