memory-internal.h: Remove obsolete claim that header is obsolete

The memory-internal.h header claims that it is for "obsolete
exec.c functions" which "will be removed soon". This statement
was added in 2011, six years ago, but the header is still here.
(Admittedly none of the prototypes added in commit 67d95c15
are still in the header.)

It's convenient to have a place to put prototypes for functions
which are used internally to the various .c files of the memory
system or by the accel/tcg code, which is inevitably fairly
closely coupled. So keep the header but update the comments to
reflect what we're actually using it for.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-Id: <1511276888-17834-1-git-send-email-peter.maydell@linaro.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

include/exec/memory-internal.h

 /*
- * Declarations for obsolete exec.c functions
+ * Declarations for functions which are internal to the memory subsystem.
  *
  * Copyright 2011 Red Hat, Inc. and/or its affiliates
  *
@@ -12,8 +12,9 @@
  */
 
 /*
- * This header is for use by exec.c and memory.c ONLY.  Do not include it.
- * The functions declared here will be removed soon.
+ * This header is for use by exec.c, memory.c and accel/tcg/cputlb.c ONLY,
+ * for declarations which are shared between the memory subsystem's
+ * internals and the TCG TLB code. Do not include it from elsewhere.
  */
 
 #ifndef MEMORY_INTERNAL_H