staging: wilc1000: fix WEP security bug

Station cannot connect to soft AP mode wilc when it is configured for WEP
security. This patch fixes it by setting the key index within the key value and
change the last else condition with DEFAULTKEY action case, and also do not use
WILC_WFI_wep_default index to set wep key id.

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