Add initial support for Ingenic X1000 SoC and Y&A CU Neo board v4.

From: Zhou Yanjie
Date: Tue Nov 26 2019 - 12:07:21 EST


1.Adjust the description in "devices.yaml" to make it more reasonable.
2.Adjust "model" in "cu1000.dts" to match the description in "devices.yaml".
3.Adjust "bool" in "Kconfig" to avoid duplicate names with subsequent boards.
4.Add pdma controller DT node and Update defconfig for pdma controller.