wayland: add build time dependency to libffi

package/wayland/Makefile

@@ -9,7 +9,7 @@ PKG_RELEASE:=		1
 PKG_HASH:=		864fb2a8399e2d0ec39d56e9d9b753c093775beadc6022ce81f441929a81e5ed
 PKG_DESCR:=		wayland
 PKG_SECTION:=		x11/libs
-PKG_BUILDDEP:=		wayland-host
+PKG_BUILDDEP:=		wayland-host libffi
 HOST_BUILDDEP:=		meson-host expat-host libxml2-host libffi-host
 PKG_SITES:=		https://gitlab.freedesktop.org/wayland/wayland/-/releases/$(PKG_VERSION)/downloads/
 PKG_OPTS:=		dev