libnsl: add knob to disable it

It's a dummy either way.

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

extra/Configs/Config.in

@@ -1191,6 +1191,12 @@ config UCLIBC_HAS_RESOLV_STUB
 	help
 	  Provide a dummy resolv library.
 
+config UCLIBC_HAS_LIBNSL_STUB
+	bool "Provide libnsl stub"
+	default n
+	help
+	  Provide a dummy nsl library.
+
 endif
 
 

libnsl/Makefile.in

@@ -28,8 +28,8 @@ libnsl-a-y := $(libnsl_OBJ)
 endif
 libnsl-so-y := $(libnsl_OBJ:.o=.os)
 
-lib-a-y += $(top_builddir)lib/libnsl.a
-lib-so-y += $(top_builddir)lib/libnsl.so
+lib-a-$(UCLIBC_HAS_LIBNSL_STUB) += $(top_builddir)lib/libnsl.a
+lib-so-$(UCLIBC_HAS_LIBNSL_STUB) += $(top_builddir)lib/libnsl.so
 objclean-y += libnsl_clean
 
 ifeq ($(DOPIC),y)