arm64: dts: imx8mq: Add the opp table and cores opp properties

Add the 0.8GHz and 1GHz opps. According to the datasheet:
https://www.nxp.com/docs/en/data-sheet/IMX8MDQLQIEC.pdf


section 3.1.3 Operating ranges.

The 0.8GHz opp runs in nominal mode with the regulator set to 0.9V.
The 1GHz runs in overdrive mode with the regulator set to 1V.

Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>