staging: ks7010: move two preprocessor definitions to ks_wlan.h

In ks_wlan_translate_scan function there are two preprocessor
definitions:

    - RSN_INFO_ELEM_ID
    - GENERIC_INFO_ELEM_ID

These can be moved to common ks_wlan.h because they can be used
in get_current_ap function instead of use hardcoded values.
GENERIC_INFO_ELEM_ID has been renamed to WPA_INFO_ELEM_ID which
is more clear.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>