mxc91231: use MXC91231_IO_ADDRESS instead of MXC91231_AIPS1_IO_ADDRESS

Apart from MXC91231_IO_ADDRESS itself this was the only usage of
MXC91231_AIPS1_IO_ADDRESS.  Now MXC91231_IO_ADDRESS can be recoded with
IMX_IO_ADDRESS and all helper macros can go away.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Daniel Schaeffer <daniel.schaeffer@timesys.com>
Cc: Alberto Panizzo <maramaopercheseimorto@gmail.com>
Cc: Ivo Clarysse <ivo.clarysse@gmail.com>