CONFIGURE: Add plugin support for the GP2X backend.

I'll switch the GP2X to use plugins by default for new releases after some additional testing.

svn-id: r52153

configure

@@ -1944,6 +1944,24 @@ CXXFLAGS        += -fpic
 PLUGIN_LDFLAGS  += -shared
 PRE_OBJS_FLAGS  := -Wl,-export-dynamic -Wl,-whole-archive
 POST_OBJS_FLAGS := -Wl,-no-whole-archive
+'
+		;;
+	gp2x*)
+_def_plugin='
+#define PLUGIN_PREFIX	""
+#define PLUGIN_SUFFIX	".plugin"
+'
+_mak_plugins='
+DYNAMIC_MODULES := 1
+PLUGIN_PREFIX :=
+PLUGIN_SUFFIX := .plugin
+PLUGIN_EXTRA_DEPS = $(EXECUTABLE)
+CXXFLAGS        += -DDYNAMIC_MODULES
+CXXFLAGS        += -fpic
+PLUGIN_LDFLAGS  += -shared
+PRE_OBJS_FLAGS  := -Wl,-export-dynamic -Wl,-whole-archive
+POST_OBJS_FLAGS := -Wl,-no-whole-archive
+LIBS            += -ldl
 '
 		;;
 	gp2xwiz*)