KVM: selftests: aarch64: Add test_inject_fail to vgic_irq

Add tests for failed injections to vgic_irq. This tests that KVM can
handle bogus IRQ numbers.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
Acked-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211109023906.1091208-14-ricarkol@google.com