ACPI: thinkpad-acpi: bump up version to 0.19

The major code reorganization and cleanups, and new HKEY events, plus
poll()/select() support are good reasons to checkpoint a new version...

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