hamlib: fix -Wimplicit-function-declaration

srcpkgs/hamlib/patches/implicit-function-decl.patch

@@ -0,0 +1,10 @@
+--- a/tests/memload.c
++++ b/tests/memload.c
+@@ -22,6 +22,7 @@
+ #include <hamlib/config.h>
+ 
+ #include <hamlib/rig.h>
++#include <stdlib.h>
+ #include "misc.h"
+ 
+ #ifdef HAVE_XML2