arm64: dts: mediatek: add support for MT8370 SoC

arm64: dts: mediatek: add support for MT8370 SoC

Add the support of the Mediatek MT8370 SoC, a less powerful variant of
MT8390 SoC.
Their main differences are:
- Arm Cortex-A55 cores number (4 vs 6)
- Arm Cortex-A78 core speed (2.0 GHz vs 2.2 Ghz)
- Arm Mali-G57 GPU core number (2 vs 3)

Like MT8390, MT8370 hardware register maps are identical to MT8188.

Note:
The devicetree for MT8370 SoC does not currently contain the needed
overrides to support the Mali GPU integrated into this SoC. This is
scheduled to be done with a later change.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Louis-Alexis Eyraud <louisalexis.eyraud@collabora.com>
Link: https://lore.kernel.org/r/20250206-dts_mt8370-genio-510-v3-2-5ca5c3257a4c@collabora.com
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>