ARM: dts: rockchip: Sync rk3288-vyasa dts from Linux

Sync rk3288-vyasa board dts from Linux for proper updates and maintenance
- rk3288-vyasa.dts: Similar to Linux dts
- rk3288-vyasa-u-boot.dtsi: u-boot dts changes

Also updated MAINTAINERS for these dts files.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>