input/csv: include section nits

Rephrase the #include statements in the CSV input module. "config" is
not a system header but is provided by the application source code.
Separate the config and system and application groups (their order is
essential). Alpha-sort the files within their group for simplified
maintenance.

src/input/csv.c

@@ -17,10 +17,12 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <config.h>
+#include "config.h"
+
+#include <glib.h>
 #include <stdlib.h>
 #include <string.h>
-#include <glib.h>
+
 #include <libsigrok/libsigrok.h>
 #include "libsigrok-internal.h"