platform/x86: x86-android-tablets: Adjust Xiaomi Pad 2 bottom bezel touch buttons LED

The "input-events" LED trigger used to turn on the backlight LEDs had to
be rewritten to use led_trigger_register_simple() + led_trigger_event()
to fix a serious locking issue.

This means it no longer supports using blink_brightness to set a per LED
brightness for the trigger and it no longer sets LED_CORE_SUSPENDRESUME.

Adjust the MiPad 2 bottom bezel touch buttons LED class device to match:

1. Make LED_FULL the maximum brightness to fix the LED brightness
   being very low when on.
2. Set flags = LED_CORE_SUSPENDRESUME.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240916090255.35548-1-hdegoede@redhat.com