acpi: Support copying properties from device tree to ACPI

acpi: Support copying properties from device tree to ACPI

Some drivers in Linux support both device tree and ACPI. U-Boot itself
uses Linux device-tree bindings for its own configuration but does not use
ACPI.

It is convenient to copy these values over to the ACPI DP table for
passing to linux. Add some convenience functions to help with this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>