Patch from Deepak Saxena

This patch borrows from the uclinux source where they have moved
the per-platform code for get_irqnr_and_base, disable_fiq, and
irq_prio_table out of entry-armv.S. However, instead of putting the
macros in arch/arm/mach-$(MACHINE)/entry-header.S, we just have
it in the machine's incdir. This means we don't need the extra
complexity of creating symlink at build time. The patch also removes 
the irq_prio_table as a requirement for all machines and makes it
specific to IOC/IOMD machines. 
  
This patch drastically shrinks entry-armv.S and allows us to delete 
and add machines without having to touch generic code (there were two 
dead machines laying around in entry-armv.S).
  
Tested on IXP4xx and test-built for just about every defconfig.

Signed-off-by: Deepak Saxena
Signed-off-by: Russell King