[ARM] cputype: separate definitions, use them

Add asm/cputype.h, moving functions and definitions from asm/system.h
there.  Convert all users of 'processor_id' to the more efficient
read_cpuid_id() function.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-ixp4xx/common-pci.c b/arch/arm/mach-ixp4xx/common-pci.c
index 192538a..f74a460 100644
--- a/arch/arm/mach-ixp4xx/common-pci.c
+++ b/arch/arm/mach-ixp4xx/common-pci.c
@@ -27,6 +27,7 @@
 #include <linux/device.h>
 #include <asm/dma-mapping.h>
 
+#include <asm/cputype.h>
 #include <asm/io.h>
 #include <asm/irq.h>
 #include <asm/sizes.h>
@@ -366,15 +367,13 @@
 
 void __init ixp4xx_pci_preinit(void)
 {  
-	unsigned long processor_id;
-
-	asm("mrc p15, 0, %0, cr0, cr0, 0;" : "=r"(processor_id) :);
+	unsigned long cpuid = read_cpuid_id();
 
 	/*
 	 * Determine which PCI read method to use.
 	 * Rev 0 IXP425 requires workaround.
 	 */
-	if (!(processor_id & 0xf) && cpu_is_ixp42x()) {
+	if (!(cpuid & 0xf) && cpu_is_ixp42x()) {
 		printk("PCI: IXP42x A0 silicon detected - "
 			"PCI Non-Prefetch Workaround Enabled\n");
 		ixp4xx_pci_read = ixp4xx_pci_read_errata;