arch: Remove the "arch/tlb.hh" switching header.

This header is no longer used.

Change-Id: I8da7f8618d647dd11c581818c13855c4e20d32d2
Reviewed-on: https://gem5-review.googlesource.com/7351
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

src/arch/SConscript

diff --git a/src/arch/SConscript b/src/arch/SConscript
index 728377d..5ea7a6a 100644
--- a/src/arch/SConscript
+++ b/src/arch/SConscript
@@ -73,7 +73,6 @@
         registers.hh
         remote_gdb.hh
         stacktrace.hh
-        tlb.hh
         types.hh
         utility.hh
         vtophys.hh