arm64: dts: marvell: Add AP806-dual missing CPU clocks

CPU clocks have been added to AP806-quad but not to the -dual
variant.

Fixes: c00bc383 ("arm64: dts: marvell: Add cpu clock node on Armada 7K/8K")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>