luajit: add dependency dlfcn-win32

luajit.pc contains: Libs.private: -Wl,-E -lm -ldl
while the luajit website states that dlopen is only required on linux,
adding dlfcn-win32 as a dependency is probably safer for MXE than removing -ldl
especially since MXE supports dlfcn-win32 and projects which use luajit.pc are
satisfied when dlfcn-win32 was built, but not satisfied otherwise.

src/luajit.mk

@@ -8,7 +8,7 @@ $(PKG)_CHECKSUM := 2db39e7d1264918c2266b0436c313fbd12da4ceb
 $(PKG)_SUBDIR   := LuaJIT-$($(PKG)_VERSION)
 $(PKG)_FILE     := $($(PKG)_SUBDIR).tar.gz
 $(PKG)_URL      := http://luajit.org/download/$($(PKG)_FILE)
-$(PKG)_DEPS     := gcc
+$(PKG)_DEPS     := gcc dlfcn-win32
 
 define $(PKG)_BUILD
     $(MAKE) -C '$(1)' -j '$(JOBS)' \