sfc: Add and use MCDI_SET_QWORD() and MCDI_SET_ARRAY_QWORD()

No need to keep open-coding the assignment of high and low dwords.

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_mon.c
Simple merge

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

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