api/mraa: add mraa_get_pin_name

Add mraa_get_pin_name to get the real world name of the pin.

Signed-off-by: Michael Ring <mail@michael-ring.org>
Signed-off-by: Thomas Ingleby <thomas.c.ingleby@intel.com>

src/mraa.c

@@ -327,6 +327,17 @@ mraa_file_exist(char *filename) {
     return file_found;
 }
 
+char*
+mraa_get_pin_name(int pin)
+{
+    if (plat == NULL) {
+        return NULL;
+    }
+    if (pin > (plat->phy_pin_count -1) || pin < 0)
+        return NULL;
+    return (char*) plat->pins[pin].name;
+}
+
 char*
 mraa_file_unglob(char *filename) {
     glob_t results;