staging: wilc1000: remove define WILC_P2P and ifdef line

WILC_P2P is always used in the driver. So delete define WILC_P2P and ifdef line.

Signed-off-by: Glen Lee <glen.lee@atmel.com>
Signed-off-by: Tony Cho <tony.cho@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>