Add DTS for ARMv8 based broadband SoC BCM6856. bcm6856.dtsi is the
SoC description DTS header and bcm96856.dts is a simple DTS file for
Broadcom BCM96956 Reference board that only enable the UART port.
Signed-off-by: William Zhang <william.zhang@broadcom.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>