package/resiprocate: enable DES in openssl

package/resiprocate: enable DES in openssl

resiprocate security backend assumes that if openssl is enabled that
it provides DES support. However DES support in openssl has become
optional since  commit a83d418 ("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/f7def0d5706f9e6ab97accc4eaa5f512a11bcb4c

Signed-off-by: Ryan Barnett <ryan.barnett@collins.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>