ps3_gelic_wireless: Fix build failure due to missing WEXT_PRIV

The option to support the old style PSK interface in the PS3
GELIC wireless drivers requires CONFIG_WEXT_PRIV to be set

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>