iommu/hyper-v: Disable IRQ pseudo-remapping if 15 bit APIC IDs are available

If the 15-bit APIC ID support is present in emulated MSI then there's no
need for the pseudo-remapping support.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201024213535.443185-34-dwmw2@infradead.org