staging: rtl8188eu: make some arrays static in rtw_mlme_ext.c

Make some arrays that are only used in rtw_mlme_ext.c static and
remove the corresponding extern declarations from rtw_mlme_ext.h.

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