arm64: dts: berlin: PSCI-1.0 support

The firmware can support PSCI-1.0 in fact. This change also enables
suspend to ram on Marvell berlin arm64 SoC.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>