Various python3 related changes

- Use relative import for grgsm's modules
- Convert map to list
- Remove the hier_block.py workaround as as gnuradio 3.7 is no longer
  supported in this branch

Change-Id: I5ca8fd340823996e8c444aaf18ddacd85c92ab1c
diff --git a/python/trx/radio_if.py b/python/trx/radio_if.py
index 0d844c0..acbc3cd 100644
--- a/python/trx/radio_if.py
+++ b/python/trx/radio_if.py
@@ -38,7 +38,7 @@
 from gnuradio import filter
 from gnuradio.filter import firdes
 
-from dict_toggle_sign import dict_toggle_sign
+from .dict_toggle_sign import dict_toggle_sign
 
 class RadioInterface(gr.top_block):
 	# PHY specific variables