irqchip/gic-v5: Check if impl is virt capable

irqchip/gic-v5: Check if impl is virt capable

Now that there is support for creating a GICv5-based guest with KVM,
check that the hardware itself supports virtualisation, skipping the
setting of struct gic_kvm_info if not.

Note: If native GICv5 virt is not supported, then nor is
FEAT_GCIE_LEGACY, so we are able to skip altogether.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20260128175919.3828384-33-sascha.bischoff@arm.com
[maz: cosmetic changes]
Signed-off-by: Marc Zyngier <maz@kernel.org>