soc: mediatek: pwrap: Check return value of platform_get_irq()

Check for the return value of platform_get_irq(): if no interrupt
is specified, it wouldn't make sense to call devm_request_irq().

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220517104712.24579-4-angelogioacchino.delregno@collabora.com


Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>