Remove the compile time definition and make the logging be controlled
by the `-d mmu` option in the cmdline.

Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20220107222601.4101511-3-farosas@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>