MT6358 is a PMIC that is typically used on MT8183 boards, and it has
its own dtsi file, declaring interrupts-extended on its node.

The interrupt pin of that PMIC is connected to a SoC GPIO and that
is therefore not only SoC-specific, but board-specific: this means
that the interrupt-extended property does not belong to the PMIC
dtsi file, but to board files using that PMIC.

For correctness, transfer the interrupts-extended property from the
PMIC-specific mt6358.dtsi to board files.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>