hwdb: Add generic key mapping for Logitech 27 MHz keyboards
The upcoming kernel enumerates Logitech 27 MHz wireless keyboards and
mice by there wireless-PID, rather then using the PID of the receiver
which is the same for all 27MHz Logitech devices.
This will allow us to add per model keymappings for the special keys on
these keyboards, which may differ per model.
This commit adds a default / fallback mapping, assigning the most common
meaning of the custom Logitech c10XX keycodes.