[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-omap2/id.c b/arch/arm/mach-omap2/id.c
index a5d4526..2fd8a2d 100644
--- a/arch/arm/mach-omap2/id.c
+++ b/arch/arm/mach-omap2/id.c
@@ -15,6 +15,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 
+#include <asm/cputype.h>
 #include <asm/io.h>
 
 #include <mach/control.h>