libx265: add missing build dependency

package/libx265/Makefile

@@ -9,6 +9,7 @@ PKG_HASH:=		d5e75fa62ffe6ed49e691f8eb8ab8c1634ffcc0725dd553c6fdb4d5443b494a2
 PKG_RELEASE:=		1
 PKG_DESCR:=		h265 encoding library
 PKG_SECTION:=		libs/video
+PKG_BUILDDEP:=		cmake-host
 PKG_URL:=		http://x265.org
 PKG_SITES:=		https://bitbucket.org/multicoreware/x265/downloads/
 PKG_OPTS:=		dev