ARM: ixp4xx: use runtime ioremap hook

Convert ixp4xx platforms to use run-time ioremap hook instead of the
compile time hook.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Imre Kaloz <kaloz@openwrt.org>
Cc: Krzysztof Halasa <khc@pm.waw.pl>

arch/arm/mach-ixp4xx/dsmg600-setup.c

@@ -280,6 +280,7 @@ MACHINE_START(DSMG600, "D-Link DSM-G600 RevA")
 	/* Maintainer: www.nslu2-linux.org */
 	.atag_offset	= 0x100,
 	.map_io		= ixp4xx_map_io,
+	.init_early	= ixp4xx_init_early,
 	.init_irq	= ixp4xx_init_irq,
 	.timer          = &dsmg600_timer,
 	.init_machine	= dsmg600_init,