KVM: arm64: gic-v5: Set ICH_VCTLR_EL2.En on boot

KVM: arm64: gic-v5: Set ICH_VCTLR_EL2.En on boot

This control enables virtual HPPI selection, i.e., selection and
delivery of interrupts for a guest (assuming that the guest itself has
opted to receive interrupts). This is set to enabled on boot as there
is no reason for disabling it in normal operation as virtual interrupt
signalling itself is still controlled via the HCR_EL2.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Link: https://patch.msgid.link/20260319154937.3619520-37-sascha.bischoff@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>