spi: sunplus-sp7021: switch to use modern name

Change legacy name master/slave to modern name host/target or controller.

No functional changed.
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://msgid.link/r/20231128093031.3707034-9-yangyingliang@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>