configs: Set kvm_map in DRAMInterface in Ruby.py

The kvm_map parameter from AbstractMemory has been moved from MemCtrl
(formerly DRAMCtrl) to DRAMInterface. Assign it to DRAMInterface
instead.

Change-Id: I4508aefcf5eb859d9ffe05c81d85a1b84ee0a196
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35095
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/configs/ruby/Ruby.py b/configs/ruby/Ruby.py
index 622771a..86d5748 100644
--- a/configs/ruby/Ruby.py
+++ b/configs/ruby/Ruby.py
@@ -136,7 +136,7 @@
             mem_ctrl = m5.objects.MemCtrl(dram = dram_intf)
 
             if options.access_backing_store:
-                mem_ctrl.kvm_map=False
+                dram_intf.kvm_map=False
 
             mem_ctrls.append(mem_ctrl)
             dir_ranges.append(mem_ctrl.dram.range)