drivers/arm/css/scmi: Update power domain protocol version to 2.0
drivers/arm/css/scmi: Update power domain protocol version to 2.0

The SCMI power domain protocol in firmware has been updated to v2.0,
thus update the corresponding version in TF-A too.

Signed-off-by: Nicola Mazzucato <8ae2ed22373d69a18b2d6668b371b97bd4dd3e2a@arm.com>
Change-Id: If3920ff71136dce94b2780e29a47f24aa09876c0

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware