Input: Support set power/wakeup node of device

power/wakeup attribute allows the userspace to check
if the device is enabled to wake up the kernel from
sleep states. Devices support "wakeup" events can send
hardware signal to resume systems.

This change follows kernel doc:
"In that cases the user space can change the setting
represented by the contents of this file by writing
either "enabled", or "disabled" to it."

DD: go/configure-al-kernel-wake
Bug: 372812925
Test: atest inputflinger_tests
Test: Plug in USB mouse with the set of changes:
      power/wakeup of mouse becomes enabled and it can wake
      up from "echo mem > /sys/power/state".
Flag: com.android.input.flags.set_input_device_kernel_wake

Change-Id: I188c34cc645e9582d35a00a267653a0ca9c1da6e