Revert "arm64: dts: marvell: add CPU Idle power state support on Armada 7K/8K"

This reverts commit 8ed46368.

This commit breaks boot on Armada 8K based systems. Reverting it makes
affected systems boot again.

Reported-by: Sergey Matyukevich <geomatsi@gmail.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>