x86, msi, intr-remap: Use the ioapic set affinity routine

IRQ set affinity routine is same for the IO-APIC IRQ's aswell as
the MSI IRQ's in the presence of interrupt-remapping. This is
because we modify the interrupt-remapping table entry and
doesn't touch the IO-APIC RTE or the MSI entry.

So remove the ir_msi_set_affinity() and re-use the
ir_ioapic_set_affinity()

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: yinghai@kernel.org
Cc: youquan.song@intel.com
Cc: joerg.roedel@amd.com
Cc: tony.luck@intel.com
Cc: dwmw2@infradead.org
Link: http://lkml.kernel.org/r/20110824001456.452760446@sbsiddha-desk.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>