package/wpa_supplicant: enable DES in openssl

package/wpa_supplicant: enable DES in openssl

Hostapd/wpa_supplicant crypto backend assumes that openssl always
provides DES support. However DES support in openssl has become
optional since  commit a83d41867c8d ("package/libopenssl: add
option to enable some features").

Select openssl DES support in wpa_supplicant Kconfig to avoid
build failures.

Fixes:
http://autobuild.buildroot.net/results/00d46eb765f23a1f6e168338f2cc863ae348045d/

Signed-off-by: Sergey Matyukevich <geomatsi@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>