Set the CEC I2C address based on the slave I2C address.

The two LSBs of the TDA998x's I2C address are set by pins
on the chip. The associated CEC peripheral's I2C address
is set in the same way, so base the CEC address on that
of the slave's address.

Signed-off-by: Andrew Jackson <Andrew.Jackson@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Support PSCI reboot/shutdown

Hack in the extra function IDs in lieu of 'proper' PSCi 0.2 support.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>