examples/l2fwd-crypto: use key-value list of supported algorithms

examples/l2fwd-crypto: use key-value list of supported algorithms

In order to ease the parsing and display of supported algorithms
in the application, two new arrays are created, which contains
the strings of the different cipher and authentication algorithms,

These lists are used to parse the algorithms from the command line,
and will be used to display crypto information to the user.

Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
Acked-by: Declan Doherty <declan.doherty@intel.com>