ARM: dts: bcmbca: bcm6878: cosmetic change

Add new line between dts node.

Signed-off-by: William Zhang <william.zhang@broadcom.com>
Link: https://lore.kernel.org/r/20220801194754.29492-2-william.zhang@broadcom.com


Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>