spi: HiSilicon v3xx: Properly set CMD_CONFIG for Dual/Quad modes

The CMD_CONFIG register memory interface type field is not set configured
for Dual and Quad modes, so set appropriately.

This was not detected previously as we only ever operated in standard SPI
mode.

Signed-off-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1582903131-160033-3-git-send-email-john.garry@huawei.com


Signed-off-by: Mark Brown <broonie@kernel.org>