Add spi driver for Sunplus SP7021.
Signed-off-by: NLi-hao Kuo <lhjeff911@gmail.com>
Link: https://lore.kernel.org/r/37998e515d561e762ee30d0ac4fca25a948e0c5c.1642494310.git.lhjeff911@gmail.comSigned-off-by: NMark Brown <broonie@kernel.org>