arch: arm64: fix the wrong way to send ipi interrupt

On GICv3, when we send an IPI interrupt, aff3, aff2 and aff1 should
be assigned a value corespond to a PE for which interrupt will be
generated. target_list only corresponds to aff0.

On real hardware, aff3, aff2, aff1 and aff0 should be treated as a
whole to determine a PE.

Signed-off-by: Huifeng Zhang <Huifeng.Zhang@arm.com>