PERENTIE-2404: update P4 code ref to 0.5.6
Version 0.5.6 fixes a critical bug affecting ARP resolution between CSP and SDP. This fix is backward-compatible, so I've updated the default here rather than overriding the variable in ska-ser-baremetal.
Version 0.5.6 fixes a critical bug affecting ARP resolution between CSP and SDP. This fix is backward-compatible, so I've updated the default here rather than overriding the variable in ska-ser-baremetal.