gpio: virtio: support multiple virtio-gpio controller instances

gpio: virtio: support multiple virtio-gpio controller instances

Modify the virtio-gpio driver to support multiple virtual GPIO controller
instances. The previous static global irq_chip structure caused conflicts
between multiple virtio-gpio device instances as they shared the same
interrupt controller configuration.

Fix this by:
1. Remove the static global vgpio_irq_chip structure
2. Dynamically allocate a dedicated irq_chip for each virtio-gpio instance
3. Use device-specific names for each instance's irq_chip

Signed-off-by: hlleng <a909204013@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20250210114935.204309-1-a909204013@gmail.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>