HID: steelseries: Add capacity_level mapping

HID: steelseries: Add capacity_level mapping

The capacity level mappings are taken from:
https://support.steelseries.com/hc/en-us/articles/360049205612-How-do-I-know-the-Arctis-battery-level-how-do-I-charge-the-Arctis

Even if we have a percentage, exporting a capacity_level that matches
with the hardware warning levels means that upower can show warnings at
the same time as the hardware. So the headset starts beeping at the same
time as the critical warning notification appears :eyeroll:

Signed-off-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Jiri Kosina <jkosina@suse.com>