ACPI: OSL: Use spin locks without disabling interrupts

After commit 7a36b901 ("ACPI: OSL: Use a threaded interrupt handler
for SCI") any ACPICA code never runs in a hardirq handler, so it need
not dissable interrupts on the local CPU when acquiring a spin lock.

Make it use spin locks without disabling interrupts.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>