x86: Add proper vector accounting for HYPERVISOR_CALLBACK_VECTOR

HyperV abuses a device interrupt to account for the
HYPERVISOR_CALLBACK_VECTOR.

Provide proper accounting as we have for the other vectors as well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: x86 <x86@kernel.org>
Link: http://lkml.kernel.org/r/20140223212738.681855582@linutronix.de


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>