staging: rtl8188eu: remove redundant declaration in rtw_mlme_ext.c

The array REALTEK_96B_IE is already declared in rtw_mlme.h,
so remove the declaration in rtw_mlme_ext.c.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>