posix: streams: add stub for missing putpmsg() function

The putpmsg() function was left unimplemented when other
functions in the _XOPEN_STREAMS Option.

Add a stub to complete the Option.

Signed-off-by: Chris Friedt <cfriedt@tenstorrent.com>
diff --git a/lib/posix/options/stropts.c b/lib/posix/options/stropts.c
index c1e6c9f..dab6ea9 100644
--- a/lib/posix/options/stropts.c
+++ b/lib/posix/options/stropts.c
@@ -19,6 +19,19 @@
 	return -1;
 }
 
+int putpmsg(int fildes, const struct strbuf *ctlptr, const struct strbuf *dataptr, int band,
+	    int flags)
+{
+	ARG_UNUSED(fildes);
+	ARG_UNUSED(ctlptr);
+	ARG_UNUSED(dataptr);
+	ARG_UNUSED(band);
+	ARG_UNUSED(flags);
+
+	errno = ENOSYS;
+	return -1;
+}
+
 int fdetach(const char *path)
 {
 	ARG_UNUSED(path);