spi: ingenic: Add support for new Ingenic SoCs.

1.Since it would be dangerous to specify a newer SoC's compatible
  string as the fallback of an older SoC's compatible string, we
  add support for the "ingenic,jz4775-spi" compatible string in
  the driver.

  This will permit to support the JZ4775 by having:
  compatible = "ingenic,jz4775-spi";

  Instead of doing:
  compatible = "ingenic,jz4775-spi", "ingenic,jz4780-spi";

2.Add support for probing the spi-ingenic driver on the X1000 SoC
  from Ingenic. From the X1000 SoC onwards, the maximum frequency
  allowed by the SSI module of Ingenic SoCs has been changed from
  54MHz to 50MHz. So "max_speed_hz" is introduced in "jz_soc_info"
  to set different maximum frequency values.

3.Add support for probing the spi-ingenic driver on the X2000 SoC
  from Ingenic. The X2000 SoC has only one native chip select line,
  so "max_native_cs" is introduced in "jz_soc_info" to set different
  maximum number of native chip select lines.

4.Because of the introduction of support for the X-series SoCs, the
  current driver is not only applicable to the JZ-series SoCs, so
  the description texts has been modified to avoid misunderstanding.

Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/1650724725-93758-4-git-send-email-zhouyanjie@wanyeetech.com


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