save_and_disable_irqs does not need to use mov + msr (which was
introduced to work around a documentation bug which was propagated
into binutils.)  Use msr with an immediate constant, and if we're
building for ARMv6 or later, use the new CPSID instruction.
Signed-off-by: NRussell 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!