arm64: dts: imx8mq-evk: link regulator to VPU domain

The SW1C regulator powers the VPU and the state isn't guaranteed
to always be on.  Link the VPU power-domain to the regulator to
ensure it is turned on before using the power domain.

Signed-off-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>