KVM: x86: set KVM_REQ_EVENT on local interrupt request from user space

Set KVM_REQ_EVENT when a PIC in user space injects a local interrupt.

Currently a request is only made when neither the PIC nor the APIC is in
the kernel, which is not sufficient in the split IRQ chip case.

This addresses a problem in QEMU where interrupts are delayed until
another path invokes the event loop.

Reviewed-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Matt Gingell <gingell@google.com>
Fixes: 1c1a9ce9
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>