arm64: dts: exynos: Add Exynos9810 SoC support

arm64: dts: exynos: Add Exynos9810 SoC support

Exynos 9810 is an ARMv8 mobile SoC found in various Samsung devices,
such as Samsung Galaxy S9 (starlte), S9 Plus (star2lte),
Note 9 (crownlte) and perhaps others.

Add minimal support for this SoC, including basic stuff like:
- PSCI for bringing up secondary cores
- ARMv8 generic timer
- GPIO and pinctrl.

The firmware coming with the devices based on this SoC is buggy
and doesn't configure CNTFRQ_EL0, as required by spec, so it's
needed to hardcode the frequency in the timer node.

Co-developed-by: Maksym Holovach <nergzd@nergzd723.xyz>
Signed-off-by: Maksym Holovach <nergzd@nergzd723.xyz>
Signed-off-by: Markuss Broks <markuss.broks@gmail.com>
Link: https://lore.kernel.org/r/20241214-exynos9810-v4-1-4e91fbbc2133@gmail.com
[krzysztof: Rename and move PMU nodes to proper sorting position]
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>