pylibfdt: fdt_get_mem_rsv returns 2 uint64_t values

Fix typemap for fdt_get_mem_rsv so it returns 64-bit values.

Fixes https://github.com/dgibson/dtc/issues/15.

Signed-off-by: Dan Horák <dan@danny.cz>
[dwg: Adjusted commit message for typo and context]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

pylibfdt/libfdt.i

@@ -1068,7 +1068,7 @@ typedef uint32_t fdt32_t;
 }
 
 %typemap(argout) uint64_t * {
-        PyObject *val = PyLong_FromUnsignedLong(*arg$argnum);
+        PyObject *val = PyLong_FromUnsignedLongLong(*arg$argnum);
         if (!result) {
            if (PyTuple_GET_SIZE(resultobj) == 0)
               resultobj = val;