staging: wfx: fix hif_set_mfp() with big endian hosts

struct hif_mib_protected_mgmt_policy is an array of u8. There is no
reason to swap its bytes.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20191217161318.31402-10-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>