examples/ipsec-secgw: fix default configuration

examples/ipsec-secgw: fix default configuration

Update default configuration of ipsec-secgw:
1.In ep0.cfg change SPI value used by two inbound IPv6 security
policies from 15 to 115 and 16 to 116 to point to existing inbound
SAs. There are no inbound SAs with SPI value 15, 16.
- In ep1.cfg change SPI value used by two outbound IPv6 security
policies from 15 to 115 and 16 to 116 to point to existing outbound
SAs. There are no outbound SAs with SPI value 15, 16. Add missing
priority parameter in two inbound IPv4 security policies.

Fixes: 60a94afefc84 ("examples/ipsec-secgw: add sample configuration files")
Cc: stable@dpdk.org
Signed-off-by: Lukasz Bartosik <lbartosik@marvell.com>
Acked-by: Anoob Joseph <anoobj@marvell.com>
Acked-by: Akhil Goyal <akhil.goyal@nxp.com>