Patch from Ben Dooks

This has been broken for a while now, so fix the
problems with the code, test and bring up to date.
This also makes the code conditional on an
Kconfig option
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This is part of Thomas Gleixner's generic IRQ patch, which converts
ARM to use the generic IRQ subsystem.  Here, we wrap calls to
desc->handler() in an inline function, desc_handle_irq().  This
reduces the size of Thomas' patch since the changes become more
localised.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!