net/sfc/base: add equal stride super-buffer prefix layout
net/sfc/base: add equal stride super-buffer prefix layout

Signed-off-by: Andrew Rybchenko <ac94ab2a8fe9a9a087f6e24dcbc16626b52c07e8@solarflare.com>

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