arch, arm: Print value being ignored on DummyISA write

When ignoring writes to the Dummy ISA device (DummyISADevice),
additionally print the value being ignored in the diagnostic.

Sometimes it is useful to know exactly what we are dropping ...

Change-Id: I9a01623611f0da0aa12b065fbb2031aa27e2c036
Signed-off-by: Sean McGoogan <Sean.McGoogan@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5731
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

src/arch/arm/isa_device.cc

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 ARM Limited
+ * Copyright (c) 2014,2017 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
@@ -60,7 +60,9 @@ BaseISADevice::setISA(ISA *_isa)
 void
 DummyISADevice::setMiscReg(int misc_reg, MiscReg val)
 {
-    warn("Ignoring write to miscreg %s\n", miscRegName[misc_reg]);
+    warn("Ignoring write of 0x%lx to miscreg %s\n",
+          val,
+          miscRegName[misc_reg]);
 }
 
 MiscReg