examples/ipsec-secgw: rename SP config
examples/ipsec-secgw: rename SP config

Modify the default SP config variables names to be consistent with SA.

The resulting naming convention is that variables with suffixes _out/_in
are the default for ep0 and the reverse for ep1.

Signed-off-by: Sergio Gonzalez Monroy <efb28dd1236fe58fb57f933212eddfe89b9da704@intel.com>
Acked-by: Pablo de Lara <28355d9cfe41bb8148aea0fb24f47aae8f4217a1@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk