irqchip/gic-v4: Always configure affinity on VPE activation

There are currently two paths to set the initial affinity of a VPE:

 - at activation time on GICv4 without the stupid VMOVP list, and
   on GICv4.1

 - at map time for GICv4 with VMOVP list

The latter location may end-up modifying the affinity of VPE that is
currently running, making the results unpredictible.

Instead, unify the two paths, making sure to set the initial affinity only
at activation time.

Reported-by: Nianyao Tang <tangnianyao@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nianyao Tang <tangnianyao@huawei.com>
Link: https://lore.kernel.org/r/20240705093155.871070-2-maz@kernel.org