ARM: dts: bcmbca: bcm6846: clean up psci node

Remove unnecessary cpu_on and cpu_off properties from psci
node as they are only needed for psci version prior to 0.2.

Fixes: de1a99ac ("ARM: dts: Add DTS files for bcmbca SoC BCM6846")
Signed-off-by: William Zhang <william.zhang@broadcom.com>
Link: https://lore.kernel.org/r/20220801194647.29437-2-william.zhang@broadcom.com


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