package/matchbox: xlib_libXfixes is an optional dependency

matchbox can use xlib_libXfixes to completely and really hide the
cursor, so build-depend on it if enabled.

Reported-by: Arnout Vandecappelle <arnout@mind.be>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/matchbox/matchbox.mk

@@ -39,4 +39,8 @@ ifeq ($(BR2_PACKAGE_XLIB_LIBXCURSOR),y)
 MATCHBOX_DEPENDENCIES += xlib_libXcursor
 endif
 
+ifeq ($(BR2_PACKAGE_XLIB_LIBXFIXES),y)
+MATCHBOX_DEPENDENCIES += xlib_libXfixes
+endif
+
 $(eval $(autotools-package))