arm64: dts: renesas: r8a779a0: Drop power-domains property from GIC node

arm64: dts: renesas: r8a779a0: Drop power-domains property from GIC node

"make dtbs_check":

    arm64/boot/dts/renesas/r8a779a0-falcon.dt.yaml: interrupt-controller@f1000000: 'power-domains' does not match any of the regexes: '^(msi-controller|gic-its|interrupt-controller)@[0-9a-f]+$', '^gic-its@', '^interrupt-controller@[0-9a-f]+$', 'pinctrl-[0-9]+'
	    From schema: Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.yaml

Remove the "power-domains" property, as the GIC on R-Car V3U is
always-on, and not part of a clock domain.

Fixes: 834c310f541839b6 ("arm64: dts: renesas: Add Renesas R8A779A0 SoC support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/a9ae5cbc7c586bf2c6b18ddc665ad7051bd1d206.1622560236.git.geert+renesas@glider.be