hid: cp2112: Fix IRQ shutdown stopping polling for all IRQs on chip

hid: cp2112: Fix IRQ shutdown stopping polling for all IRQs on chip

Previously cp2112_gpio_irq_shutdown() always cancelled the
gpio_poll_worker, even if other IRQs were still active, and did not set
the gpio_poll flag to false. This resulted in any call to _shutdown()
resulting in interrupts no longer functioning on the chip until a
_remove() occurred (a.e. the cp2112 is unplugged or system rebooted).

Only cancel polling if all IRQs are disabled/masked, and correctly set
the gpio_poll flag, allowing polling to restart when an interrupt is
next enabled.

Signed-off-by: Danny Kaehn <danny.kaehn@plexus.com>
Fixes: 13de9cca514e ("HID: cp2112: add IRQ chip handling")
Link: https://lore.kernel.org/r/20231011182317.1053344-1-danny.kaehn@plexus.com
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>