arm64: dts: imx8mm-kontron: Make sure SOC and DRAM supply voltages are correct

commit 82a4f329 upstream.

It looks like the voltages for the SOC and DRAM supply weren't properly
validated before. The datasheet and uboot-imx code tells us that VDD_SOC
should be 800 mV in suspend and 850 mV in run mode. VDD_DRAM should be
950 mV for DDR clock frequencies of up to 1.5 GHz.

Let's fix these values to make sure the voltages are within the required
range.

Fixes: 8668d8b2

 ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
Cc: stable@vger.kernel.org
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>