[oe] Impending Kexec interface change

[Richard Purdie]

Anyone watching mainline kernels will note that ARM kexec support got
merged and will be in 2.6.21 which is good. The issue is that the
syscall number had to change since the one its using at the moment is a
big hack.

This means we will have to change kexec-tools and at that point it
becomes incompatible with older kernels.

We can wait a bit and change when 2.6.21 is released, or update all our
patches now to use the new proper syscall number and update OE now.

I know the NSLU2 people are users of this and would value their input.

Cheers,

Richard