fix build without libsigrokdecode

When built with libsigrokdecode additional headers are automagically included
via the Python.h header. When built without they must included explicitly.

input.c

@@ -19,6 +19,10 @@
 
 #include "sigrok-cli.h"
 #include "config.h"
+#include <sys/stat.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
 #include <glib.h>
 
 extern gchar *opt_input_file;

main.c

@@ -19,6 +19,7 @@
 
 #include "sigrok-cli.h"
 #include "config.h"
+#include <stdlib.h>
 #include <glib.h>
 
 struct sr_context *sr_ctx = NULL;

sigrok-cli.h

@@ -54,6 +54,7 @@ void run_session(void);
 void load_input_file(void);
 
 /* decode.c */
+#ifdef HAVE_SRD
 int register_pds(const char *opt_pds, char *opt_pd_annotations);
 int setup_pd_stack(char *opt_pds, char *opt_pd_stack, char *opt_pd_annotations);
 int setup_pd_annotations(char *opt_pd_annotations);
@@ -62,6 +63,7 @@ int setup_pd_binary(char *opt_pd_binary);
 void show_pd_annotations(struct srd_proto_data *pdata, void *cb_data);
 void show_pd_meta(struct srd_proto_data *pdata, void *cb_data);
 void show_pd_binary(struct srd_proto_data *pdata, void *cb_data);
+#endif
 
 /* parsers.c */
 GSList *parse_probestring(struct sr_dev_inst *sdi, const char *probestring);