nrf/main: Add /flash and /flash/lib to sys.path.

This allows to follow good practice and have libraries live in the lib
folder which means they will be found by the runtime without adding this
path manually at runtime.
Signed-off-by: Sebastian Romero <s.romero@arduino.cc>

ports/nrf/main.c

@@ -191,6 +191,9 @@ soft_reset:
 
     if (ret != 0) {
         printf("MPY: can't mount flash\n");
+    } else {
+        mp_obj_list_append(mp_sys_path, MP_OBJ_NEW_QSTR(MP_QSTR__slash_flash));
+        mp_obj_list_append(mp_sys_path, MP_OBJ_NEW_QSTR(MP_QSTR__slash_flash_slash_lib));
     }
     #endif
 

ports/nrf/qstrdefsport.h

@@ -29,6 +29,7 @@
 
 // Entries for sys.path
 Q(/flash)
+Q(/flash/lib)
 
 // For os.sep
 Q(/)