staging: wilc1000: avoid use of interface names for validation

Avoid use of interface name i.e 'wlan0' & 'p2p0' to check the interface
type in dev_state_ev_handler(). Now making use of netdev_ops and iface
type to know interface. Reorder the functions to avoid the forward
declaration after the above changes

Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>