ACPI: thinkpad-acpi: debug facility to emulate the rf switches

This code is required to keep the thinkpad-acpi maintainer sane, and
it is disabled by default.

Add a debug facility to simulate an rfkill hardware rocker switch, a
bluetooth rfkill soft-switch, a WWAN rfkill soft-switch on thinkpads.

The simulated switches obviously do not kill any radios in hardware or
firmware (unlike the real one).  They also don't issue deprecated proc
events.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>