ACPI: thinkpad-acpi: add sysfs support to hotkey subdriver

Add the hotkey sysfs support.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/misc/thinkpad_acpi.h b/drivers/misc/thinkpad_acpi.h
index a9e7093..7615adb 100644
--- a/drivers/misc/thinkpad_acpi.h
+++ b/drivers/misc/thinkpad_acpi.h
@@ -414,6 +414,8 @@
  * Hotkey subdriver
  */
 
+#define TPACPI_HOTKEY_SYSFS_GROUP "hotkey"
+
 static int hotkey_orig_status;
 static int hotkey_orig_mask;