arm64: dts: broadcom: bcm4908: add LEDs controller block

BCM4908 includes LEDs controller that supports multiple brightness
levels & hardware blinking.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20220718132100.13277-2-zajec5@gmail.com


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