gateware: fix some issues introduced with cleanup

gateware/led.py

@@ -1,5 +1,6 @@
 from amaranth import *
 from amaranth_soc.wishbone import *
+from amaranth_soc.memory import *
 
 
 class LEDPeripheral(Elaboratable, Interface):

gateware/main.py

@@ -10,6 +10,9 @@ from minerva.core import Minerva
 from typing import List
 from argparse import ArgumentParser
 
+from memory import *
+from led import *
+
 
 # To change clock domain of a module:
 # new_thing = DomainRenamer("new_clock")(MyElaboratable())