platforms/sipeed_tang_nano_4k: add P6 and P7 connectors

litex_boards/platforms/sipeed_tang_nano_4k.py

@@ -69,7 +69,10 @@ _io = [
 
 # Connectors ---------------------------------------------------------------------------------------
 
-_connectors = []
+_connectors = [
+    ["P6", "30 29 28 27 23 22 21 20 19 18 17 13 16  9  8 33  2  -  -  -  - 15"],
+    ["P7", "31 32 34 35 10 39 40 41 42 43 47 48  1 46 44  -  -  6  3  4  7 14"],
+]
 
 # Platform -----------------------------------------------------------------------------------------