Patch from Nicolas Pitre

The change as seen here:
http://linux.bkbits.net:8080/linux-2.5/diffs/arch/arm/kernel/head.S@1.19?nav=index.html|ChangeSet@-4d|cset@1.1769.3.12
has this note:
"No need to include asm/mach/arch.h"
But it now requires asm/constants.h otherwise SIZEOF_MACHINE_DESC
is not defined.  Why compilation succeeds anyways still mystify me.