cpu,fastmodel: Eliminate the now unnecessary initMemProxies method.

The proxies this method initializes no longer exist, since they're now
created locally.

Change-Id: I5fd1c99fbc00f5057ea8868e91be02d577b1c176
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/45909
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/cpu/kvm/base.cc

@@ -109,11 +109,7 @@ void
 BaseKvmCPU::init()
 {
     BaseCPU::init();
-
-    if (numThreads != 1)
-        fatal("KVM: Multithreading not supported");
-
-    tc->initMemProxies(tc);
+    fatal_if(numThreads != 1, "KVM: Multithreading not supported");
 }
 
 void