leds: add LED control [LoungeKat]
Ref: https://github.com/StarKissed/starkissed-kernel-trlte

4. fix spelling error in the notification sysfs
commit: 3d799b5e26ac36d31450651a06a277ee03f14941

3. resolve scope and forward declaration issues
commit: 7ef07791ab023fc4fef1d9dffe76d643b03d241b

2. add LED userspace ramp / delay control
commit: 27533b820e71a040fcceb432d02b5fb05c039615

1. Modified based on friedrich420/S4-TW-AEL-Kernel-v4Plus@3f4a6d5 84c744b3f1d9005bca70fd46fd008da
commit: b4f35bf6bd5f05c0641c8a307f409fa55a125015