sfc: Allow efx_nic_type::dimension_resources to fail

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/net_driver.h
Simple merge

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