SPI: add Ingenic JZ47xx driver.

Add a driver to support the SPI controller found in Ingenic SoCs.

Co-developed-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
Link: https://lore.kernel.org/r/20210830230139.21476-3-contact@artur-rojek.eu


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