Revert "ACPI: SCI interrupt source override"

This reverts commit 281ea49b,
which broke ACPI Interrupt source overrides that move
the SCI from one IRQ in PIC mode to another in IOAPIC mode.

If the SCI shared an interrupt line with another device,
this would result in a "irq 18: nobody cared" type failure.

http://bugzilla.kernel.org/show_bug.cgi?id=7601



Signed-off-by: Len Brown <len.brown@intel.com>