The s3fwrn5_phy_ops structure is never modified, so declare it as const.

Done with the help of Coccinelle.
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Acked-by: NRobert Baldyga <r.baldyga@samsung.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>