Distribute position.h for mozilla plugin

Signed-off-by: Rémi Duraffort <ivoire@videolan.org>
(cherry picked from commit 9c2cc4528e6efdb2d9a838212e7dfbf3d4f47fa7)

projects/mozilla/Makefile.am

@@ -15,6 +15,7 @@ SOURCES_mozilla_common = \
 	control/npolibvlc.h \
 	control/nporuntime.cpp \
 	control/nporuntime.h \
+	control/position.h \
 	support/classinfo.h
 
 DIST_sources = $(SOURCES_mozilla_common) \