KVM: arm64: Turn kvm_vgic_vcpu_enable() into kvm_vgic_vcpu_reset()

KVM: arm64: Turn kvm_vgic_vcpu_enable() into kvm_vgic_vcpu_reset()

Now that we always reconfigure the vgic HCR register on entry,
the "enable" part of kvm_vgic_vcpu_enable() is pretty useless.

Removing the enable bits from these functions makes it plain that
they are just about computing the reset state. Just rename the
functions accordingly.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-23-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>