swig: Add support for isr/callbacks from python

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

examples/python/hello_isr.py

@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+
+import pymaa as maa
+
+def test():
+  print("wooo")
+
+x = maa.Gpio(6)
+x.dir(maa.MAA_GPIO_IN)
+x.set_isr(test)