Merge branches 'irq/sparseirq', 'x86/quirks' and 'x86/reboot' into cpus4096

We merge the irq/sparseirq, x86/quirks and x86/reboot trees into the
cpus4096 tree because the io-apic changes in the sparseirq change
conflict with the cpumask changes in the cpumask tree, and we
want to resolve those.