include/exec: Move cputlb exec.c defs out

Move the architecture agnostic function prototypes for exec.c out of
cputlb.h to exec-all.h. This allows hiding of the arch specific
cputlb.h from exec.c which should be getting close to having no
architecture specifics. Prepares support for multi-arch, which will have
a minimal cpu.h that services exec.c but not cputlb.h.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Message-Id: <b4fe754c58c860315e35d44430c26b1c967ce2c9.1441614289.git.crosthwaite.peter@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>