KVM: arm64: Treat vCPU with pending SError as runnable

Per R_VRLPB, a pending SError is a WFI wakeup event regardless of
PSTATE.A, meaning that the vCPU is runnable. Sample VSE in addition to
the other IRQ lines.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250708172532.1699409-5-oliver.upton@linux.dev


Signed-off-by: Oliver Upton <oliver.upton@linux.dev>