arm64: dts: imx8-ss-lsio: Add PWM interrupts

The PWM interrupt is mandatory per imx-pwm.yaml.

Add them.

This also fixes the followig schema warning:

imx8qm-apalis-v1.1-ixora-v1.2.dtb: pwm@5d000000: 'oneOf' conditional failed, one must be fixed:
	'interrupts' is a required property
	'interrupts-extended' is a required property
	from schema $id: http://devicetree.org/schemas/pwm/imx-pwm.yaml#



Signed-off-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>