ARM: plat-mxc: Remove unused imx_ioremap

imx_ioremap is no longer used on imx platforms, so remove it.

As the EXPORT_SYMBOL_GPL is removed, it is also safe to remove the module.h header.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>