sfc: Generalise packet hash lookup to support EF10 RX prefix

EF10 uses an entirely different RX prefix format from Falcon-arch.
Extend struct efx_nic_type to describe this.

[bwh: Also replace the magic numbers used for the Falcon-arch RX prefix]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

diff --cc drivers/net/ethernet/sfc/efx.c
Simple merge

diff --cc drivers/net/ethernet/sfc/falcon.c
Simple merge

diff --cc drivers/net/ethernet/sfc/farch_regs.h
Simple merge

diff --cc drivers/net/ethernet/sfc/net_driver.h
Simple merge

diff --cc drivers/net/ethernet/sfc/rx.c
Simple merge

diff --cc drivers/net/ethernet/sfc/siena.c
Simple merge