arm_gicv3_kvm: kvm_dist_get/put_priority: skip the registers banked by GICR_IPRIORITYR

arm_gicv3_kvm: kvm_dist_get/put_priority: skip the registers banked by GICR_IPRIORITYR

While for_each_dist_irq_reg loop starts from GIC_INTERNAL, it forgot to
offset the date array and index. This will overlap the GICR registers
value and leave the last GIC_INTERNAL irq's registers out of update.

Fixes: 367b9f527becdd20ddf116e17a3c0c2bbc486920
Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Shannon Zhao <zhaoshenglong@huawei.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>