[ARM] 5053/1: define before use of processor_id

For the simple read_cpuid() macro case the variable processor_id has
no definition on use of the macro. Add an extern for it. Move all the
processor ID macros into the #ifndef __ASSEMBLEY__ block.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>