librt: Rephrase librt.so library dependencies

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

librt/Makefile.in

@@ -61,11 +61,14 @@ lib-a-y += $(top_builddir)lib/librt.a
 lib-so-y += $(top_builddir)lib/librt.so
 endif
 
+librt-dep-y := $(libc.depend)
+librt-dep-$(UCLIBC_HAS_THREADS_NATIVE) += $(libpthread.depend) $(libdl.depend)
+
 # for NPTL we need SHARED regardless of DOPIC
 ifeq ($(if $(UCLIBC_HAS_THREADS_NATIVE),,$(DOPIC)),y)
-$(top_builddir)lib/librt.so: $(top_builddir)lib/librt.a $(libc.depend)
+$(top_builddir)lib/librt.so: $(top_builddir)lib/librt.a $(librt-dep-y)
 else
-$(top_builddir)lib/librt.so: $(librt_OUT)/librt_so.a $(libc.depend) $(libpthread.depend) $(libdl.depend)
+$(top_builddir)lib/librt.so: $(librt_OUT)/librt_so.a $(librt-dep-y)
 endif
 	$(call link.so,$(librt_FULL_NAME),$(ABI_VERSION))