Add function to load in the GPIO data from JSON.

Use the cJSON module to load in the GPIO definitions used by
the other skeleton code into a cJSON structure.  Its memory
should be released by calling cJSON_Delete on it when complete.

This is the first commit in a series that will move the GPIO
configuration data from D-Bus into a JSON file, which is both
more appropriate for read only data and the first step in
getting rid of the system_manager.py file that currently hosts it.

Change-Id: If1ef19e7988d28e3075828f61e88a606631bcd89
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/libopenbmc_intf/gpio_json.h b/libopenbmc_intf/gpio_json.h
new file mode 100644
index 0000000..b966c98
--- /dev/null
+++ b/libopenbmc_intf/gpio_json.h
@@ -0,0 +1,15 @@
+#ifndef __GPIO_JSON_H__
+#define __GPIO_JSON_H__
+
+#include <cjson/cJSON.h>
+
+/**
+ * Loads the GPIO definitions from JSON into a cJSON structure.
+ *
+ * @return cjSON* - The structure with the GPIO info.  Should be freed
+ *                  with cJSON_Delete() when done.  NULL is returned
+ *                  if there was an error.
+ */
+cJSON* load_json();
+
+#endif