misc: Replaced master/slave terminology

Change-Id: I4df2557c71e38cc4e3a485b0e590e85eb45de8b6
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33553
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>

configs/common/FSConfig.py

@@ -98,7 +98,7 @@ def fillInCmdline(mdesc, template, **kwargs):
 def makeCowDisks(disk_paths):
     disks = []
     for disk_path in disk_paths:
-        disk = CowIdeDisk(driveID='master')
+        disk = CowIdeDisk(driveID='device0')
         disk.childImage(disk_path);
         disks.append(disk)
     return disks