Make these inline definitions "extern inline" to keep a copy of
the code in the object files.

--- drivers/input/mouse/sentelic.h	2015-03-15 20:30:43.000000000 +0100
+++ drivers/input/mouse/sentelic.h	2016-12-11 23:59:42.772013703 +0100
@@ -115,11 +115,11 @@
 extern int fsp_detect(struct psmouse *psmouse, bool set_properties);
 extern int fsp_init(struct psmouse *psmouse);
 #else
-inline int fsp_detect(struct psmouse *psmouse, bool set_properties)
+extern inline int fsp_detect(struct psmouse *psmouse, bool set_properties)
 {
 	return -ENOSYS;
 }
-inline int fsp_init(struct psmouse *psmouse)
+extern inline int fsp_init(struct psmouse *psmouse)
 {
 	return -ENOSYS;
 }
