DC: Don't set a lib search path for plugins

Plugins may not rely on external libs, so there is no point in
specifying a custom library search path for them.

configure

@@ -2349,7 +2349,7 @@ POST_OBJS_FLAGS :=
 		_plugin_suffix=".plg"
 _mak_plugins='
 PLUGIN_EXTRA_DEPS	= $(abspath $(srcdir)/backends/platform/dc/plugin.x $(srcdir)/backends/platform/dc/plugin.syms) $(EXECUTABLE) backends/platform/dc/plugin_head.o
-PLUGIN_LDFLAGS		= -ml -m4-single-only -nostartfiles -Wl,-q,-T$(srcdir)/backends/platform/dc/plugin.x,--just-symbols,$(EXECUTABLE),--retain-symbols-file,$(srcdir)/backends/platform/dc/plugin.syms -L$(ronindir)/lib backends/platform/dc/plugin_head.o
+PLUGIN_LDFLAGS		= -ml -m4-single-only -nostartfiles -Wl,-q,-T$(srcdir)/backends/platform/dc/plugin.x,--just-symbols,$(EXECUTABLE),--retain-symbols-file,$(srcdir)/backends/platform/dc/plugin.syms backends/platform/dc/plugin_head.o
 PRE_OBJS_FLAGS		:= -Wl,--whole-archive
 POST_OBJS_FLAGS		:= -Wl,--no-whole-archive
 '