soc: mediatek: mtk-svs: Switch to platform_get_irq()

soc: mediatek: mtk-svs: Switch to platform_get_irq()

Instead of using irq_of_parse_and_map() to retrieve the interrupt from
devicetree, switch to platform_get_irq() instead: this function will
conveniently also write an error message in case the irq is not found.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220726141653.177948-3-angelogioacchino.delregno@collabora.com
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>