APIC_ARBPRI is a reserved register for XAPIC and beyond.
APIC_RRR is a reserved register except for 82489DX, APIC for Pentium processors.
APIC_EOI is a write only register.
APIC_DFR is reserved in x2apic mode.

Access to these registers in x2apic will result in #GP fault. Fix these
apic register accesses.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>