mem: Fix some transitive includes.

Some headers were including base/logging.hh transitively and
accidentally through base/intmath.hh. Make the includes explicit and
direct.

Change-Id: Ie5852abaf32b3fba5001d29b3d0546103ee492b6
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/42503
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/mem/ruby/common/Histogram.cc

@@ -32,6 +32,7 @@
 #include <iomanip>
 
 #include "base/intmath.hh"
+#include "base/logging.hh"
 
 Histogram::Histogram(int binsize, uint32_t bins)
 {

src/mem/stack_dist_calc.cc

@@ -39,6 +39,7 @@
 
 #include "base/chunk_generator.hh"
 #include "base/intmath.hh"
+#include "base/logging.hh"
 #include "base/trace.hh"
 #include "debug/StackDist.hh"