ARM: dts: aspeed: tiogapass: Add VR devices

Adds voltage regulators Infineon pxe1610 devices to Facebook
tiogapass platform.

Signed-off-by: Vijay Khemka <vijaykhemka@fb.com>
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>