build-sys: uClibc does not have rpmatch()

Add simple replacement with hardcoded y/n responses to allow
compilation on systems without rpmatch().

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

include/rpmatch.h

@@ -0,0 +1,9 @@
+#ifndef PROCPS_NG_RPMATCH_H
+#define PROCPS_NG_RPMATCH_H
+
+#ifndef HAVE_RPMATCH
+#define rpmatch(r) \
+	(*r == 'y' || *r == 'Y' ? 1 : *r == 'n' || *r == 'N' ? 0 : -1)
+#endif
+
+#endif /* PROCPS_NG_RPMATCH_H */