kbuild: remove dependency on input.h from file2alias

Almost all definitions used by file2alias was already
present in mod_devicetable.h.
Added the last definition and killed the input.h usage.

The errornous include was pointed out
by: Jan Engelhardt <jengelh@linux01.gwdg.de>

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Cc: Deepak Saxena <dsaxena@plexity.net>
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index e96b2de..af04a55 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -262,6 +262,7 @@
 
 /* Input */
 #define INPUT_DEVICE_ID_EV_MAX		0x1f
+#define INPUT_DEVICE_ID_KEY_MIN_INTERESTING	0x71
 #define INPUT_DEVICE_ID_KEY_MAX		0x1ff
 #define INPUT_DEVICE_ID_REL_MAX		0x0f
 #define INPUT_DEVICE_ID_ABS_MAX		0x3f