upm.i: add stdint.i to add uinstd typemaps

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

src/upm.i

@@ -1,3 +1,4 @@
 %include "std_string.i"
+%include "stdint.i"
 
 %typemap(out) mraa_result_t = int;