clk: Ingenic: Add support for the X1830 and add USB clk for X1000.

[Zhou Yanjie]

1.Adjust existing code to make it compatible with Ingenic X1830 SoC.
2.Add support for the clocks provided by the CGU in the Ingenic X1830
  SoC, making use of the cgu code to do the heavy lifting.
3.Add USB related clock for the Ingenic X1000 SoC, and use the
  "CLK_OF_DECLARE_DRIVER" instead "CLK_OF_DECLARE" like the
  other CGU drivers.