litex/soc: update API to avoid unfortunate terms

Provides an alternate API to some functions of the SoCBusHandler and bus
Arbiter classes to allow users of the API to avoid the terms 'master'
and 'slave' in certain situations.

Signed-off-by: Alan Green <alan.green@gmail.com>

litex/soc/integration/soc.py

@@ -416,6 +416,9 @@ class SoCBusHandler(LiteXModule):
             colorer(name,    color="underline"),
             colorer("added", color="green")))
 
+    def add_controller(self, name=None, controller=None):
+        self.add_master(self, name=name, master=controller)
+
     def add_slave(self, name=None, slave=None, region=None):
         no_name   = name is None
         no_region = region is None
@@ -448,6 +451,9 @@ class SoCBusHandler(LiteXModule):
             colorer(name, color="underline"),
             colorer("added", color="green")))
 
+    def add_peripheral(self, name=None, peripheral=None, region=None):
+        self.add_slave(self, name=name, slave=peripheral, region=region)
+
     def get_address_width(self, standard):
         standard_from = self.standard
         standard_to   = standard

litex/soc/interconnect/wishbone.py

@@ -149,7 +149,12 @@ class InterconnectPointToPoint(Module):
 
 
 class Arbiter(Module):
-    def __init__(self, masters, target):
+    def __init__(self, masters=None, target=None, controllers=None):
+        assert target is not None
+        assert (masters is not None) or (controllers is not None)
+        if controllers is not None:
+            masters = controllers
+
         self.submodules.rr = roundrobin.RoundRobin(len(masters))
 
         # mux master->slave signals