linux-imx

MLK-22992 firmware: imx: scu-pd: fix wu_num

wu_num needs to be int type, u32 is not correct.

When "wakeup-irq" not included, of_property_count_u32_elems
will return a negative value. So use int.

And directly return when "wakeup-irq" not exists.

Signed-off-by: Peng Fan <peng.fan@nxp.com>