arch: Fix a fatal_if in most of the arch's process classes.

When switching an assert to a fatal while addressing recent review
feedback, I forgot to reverse the polarity of the condition, making
the fatal fire in exactly the opposite of the conditions it was meant
to.

Change-Id: Icf49864ef449052bbb0d427dca786006166575c4
Reviewed-on: https://gem5-review.googlesource.com/7381
Reviewed-by: Matthias Jung <jungma@eit.uni-kl.de>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

src/arch/alpha/process.cc

@@ -52,7 +52,7 @@ AlphaProcess::AlphaProcess(ProcessParams *params, ObjectFile *objFile)
     : Process(params, new FuncPageTable(params->name, params->pid, PageBytes),
       objFile)
 {
-    fatal_if(!params->useArchPT, "Arch page tables not implemented.");
+    fatal_if(params->useArchPT, "Arch page tables not implemented.");
     Addr brk_point = objFile->dataBase() + objFile->dataSize() +
                      objFile->bssSize();
     brk_point = roundUp(brk_point, PageBytes);