sfc: Move efx_mcdi_mac_reconfigure() to siena.c and rename

EF10 does not include a multicast hash filter, so this function is
specific to Siena.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

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

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

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