cmake: add patch

devel/cmake/patches/patch-bootstrap

@@ -0,0 +1,15 @@
+$NetBSD: patch-bootstrap,v 1.5 2021/03/31 07:44:29 adam Exp $
+
+librhash requires -lcrypto when statically linked.
+
+--- bootstrap.orig	2021-03-30 09:45:30.000000000 +0000
++++ bootstrap
+@@ -1708,7 +1708,7 @@ if test "x${bootstrap_system_librhash}" 
+     cmake_c_flags="${cmake_c_flags} ${use_librhash_flags}"
+     cmake_cxx_flags="${cmake_cxx_flags} ${use_librhash_flags}"
+   fi
+-  libs="${libs} -lrhash"
++  libs="${libs} -lrhash -lcrypto"
+ fi
+ 
+ if test "${cmake_bootstrap_generator}" = "Ninja"; then