KVM: arm64: vgic-v3: Don't advertise ICC_CTLR_EL1.SEIS

Since we are trapping all sysreg accesses when ICH_VTR_EL2.SEIS
is set, and that we never deliver an SError when emulating
any of the GICv3 sysregs, don't advertise ICC_CTLR_EL1.SEIS.
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211010150910.2911495-5-maz@kernel.org

arch/arm64/kvm/hyp/vgic-v3-sr.c

@@ -987,8 +987,6 @@ static void __vgic_v3_read_ctlr(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
 	val = ((vtr >> 29) & 7) << ICC_CTLR_EL1_PRI_BITS_SHIFT;
 	/* IDbits */
 	val |= ((vtr >> 23) & 7) << ICC_CTLR_EL1_ID_BITS_SHIFT;
-	/* SEIS */
-	val |= ((vtr >> 22) & 1) << ICC_CTLR_EL1_SEIS_SHIFT;
 	/* A3V */
 	val |= ((vtr >> 21) & 1) << ICC_CTLR_EL1_A3V_SHIFT;
 	/* EOImode */