apps: use CMake check for getopt.h

Add CMake detection for getopt.h and update json_parse.c to include it
only when HAVE_GETOPT_H is defined. Fixes AIX build failure.

apps/json_parse.c

@@ -1,7 +1,9 @@
 #include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
+#ifdef HAVE_GETOPT_H 
 #include <getopt.h>
+#endif
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>