imx/mach-mx3: use constants namespaced by the corresponding SOC (easy part)

This just leaves cpu.c, devices.c and mm.c to clean up.  As these files
are used on more than one SOC they need some more work.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Alberto Panizzo <maramaopercheseimorto@gmail.com>
Cc: Valentin Longchamp <valentin.longchamp@epfl.ch>
Cc: Daniel Mack <daniel@caiaq.de>
Cc: Guennadi Liakhovetski <lg@denx.de>
Cc: Yoichi Yuasa <yuasa@linux-mips.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Magnus Lilja <lilja.magnus@gmail.com>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Harro Haan <hrhaan@yahoo.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Luotao Fu <l.fu@pengutronix.de>
Cc: Ilya Yanok <yanok@emcraft.com>