dt-bindings: MIPS: Add X1830 based CU1830-Neo and fix bug in CU1000-Neo.

1.Add bindings for Ingenic X1830 based board, prepare for later dts.
2.The CU1000-Neo board actually uses X1000E instead of X1000, so
  the wrongly written "ingenic,x1000" in bindings should be changed
  to "ingenic,x1000e", the corresponding dts file modification will
  be made in a patch later in this series.

Tested-by: 周正 (Zhou Zheng) <sernia.zhou@foxmail.com>
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>