x86: x2apic, IR: Make config X86_UV dependent on X86_X2APIC

Instead of selecting X86_X2APIC, make config X86_UV dependent
on X86_X2APIC.

This will eliminate enabling CONFIG_X86_X2APIC with out
enabling CONFIG_INTR_REMAP.

[ Impact: cleanup ]

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Jack Steiner <steiner@sgi.com>
Cc: dwmw2@infradead.org
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Weidong Han <weidong.han@intel.com>
LKML-Reference: <20090420200450.694598000@linux-os.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>