HID: input: report battery status changes immediately

Previously, the battery status (charging/discharging) was not reported
immediately to user-space. 

For most input devices, this wasn't problematic because changing their
battery status requires connecting them to a different bus.
For example, a gamepad would report a discharging status while
connected via Bluetooth and a charging status while connected via USB.

However, certain devices are not connected or disconnected when their
battery status changes. For example, a phone battery changes its status
without connecting or disconnecting it.
In these cases, the battery status was not reported immediately to user
space.

Report battery status changes immediately to user space to support
these kinds of devices.

Fixes: a608dc1c ("HID: input: map battery system charging")
Reported-by: 卢国宏 <luguohong@xiaomi.com>
Closes: https://lore.kernel.org/linux-input/aI49Im0sGb6fpgc8@fedora/T/


Tested-by: 卢国宏 <luguohong@xiaomi.com>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>