devel/nanopb: Enable internal build option PB_ENABLE_MALLOC

... because it is needed for devel/criterion.

devel/nanopb/Makefile

 PORTNAME=	nanopb
 DISTVERSION=	0.4.6.4-3
+PORTREVISION=	1
 DISTVERSIONSUFFIX=	-gf84ad7f
 CATEGORIES=	devel
 

devel/nanopb/files/patch-pb.h

+--- pb.h.orig	2022-07-03 17:53:31 UTC
++++ pb.h
+@@ -11,7 +11,7 @@
+  *****************************************************************/
+ 
+ /* Enable support for dynamically allocated fields */
+-/* #define PB_ENABLE_MALLOC 1 */
++#define PB_ENABLE_MALLOC 1
+ 
+ /* Define this if your CPU / compiler combination does not support
+  * unaligned memory access to packed structures. Note that packed