thinkpad-acpi: enhanced debugging messages for the hotkey subdriver

Enhance debugging messages for the hotkey subdriver.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt
index 7daca05..abbbe78 100644
--- a/Documentation/laptops/thinkpad-acpi.txt
+++ b/Documentation/laptops/thinkpad-acpi.txt
@@ -1496,6 +1496,7 @@
 	0x0002			Removal
 	0x0004			RF Transmitter control (RFKILL)
 				(bluetooth, WWAN, UWB...)
+	0x0008			HKEY event interface, hotkeys
 
 There is also a kernel build option to enable more debugging
 information, which may be necessary to debug driver problems.