Revert "ARM: ixp4xx: enable multiplatform"

This reverts commit 5c94c9d4b556b6aaea19ffacabecd32625b9dfac.
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 897db5c..853aab5 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -381,6 +381,25 @@
 	  Support for Intel's 80219 and IOP32X (XScale) family of
 	  processors.
 
+config ARCH_IXP4XX
+	bool "IXP4xx-based"
+	depends on MMU
+	select ARCH_HAS_DMA_SET_COHERENT_MASK
+	select ARCH_SUPPORTS_BIG_ENDIAN
+	select CPU_XSCALE
+	select DMABOUNCE if PCI
+	select GENERIC_IRQ_MULTI_HANDLER
+	select GPIO_IXP4XX
+	select GPIOLIB
+	select HAVE_PCI
+	select IXP4XX_IRQ
+	select IXP4XX_TIMER
+	select NEED_MACH_IO_H
+	select USB_EHCI_BIG_ENDIAN_DESC
+	select USB_EHCI_BIG_ENDIAN_MMIO
+	help
+	  Support for Intel's IXP4XX (XScale) family of processors.
+
 config ARCH_DOVE
 	bool "Marvell Dove"
 	select CPU_PJ4
@@ -549,23 +568,6 @@
 
 endmenu
 
-config ARCH_IXP4XX
-	bool "IXP4xx-based"
-	select ARCH_HAS_DMA_SET_COHERENT_MASK
-	select ARCH_SUPPORTS_BIG_ENDIAN
-	select CPU_XSCALE
-	select DMABOUNCE if PCI
-	select GENERIC_IRQ_MULTI_HANDLER
-	select GPIO_IXP4XX
-	select GPIOLIB
-	select HAVE_PCI
-	select IXP4XX_IRQ
-	select IXP4XX_TIMER
-	select USB_EHCI_BIG_ENDIAN_DESC
-	select USB_EHCI_BIG_ENDIAN_MMIO
-	help
-	  Support for Intel's IXP4XX (XScale) family of processors.
-
 config ARCH_VIRT
 	bool "Dummy Virtual Machine"
 	depends on ARCH_MULTI_V7