pinctrl: Ingenic: Add missing parts for X1000 and X1500.

1.Add pinctrl drivers for the SPI flash controller (SFC) of
  X1000 and X1500.
2.Add pinctrl driver for the synchronous serial interface (SSI)
  of X1000.

Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Link: https://lore.kernel.org/r/1576426864-35348-4-git-send-email-zhouyanjie@wanyeetech.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>