KVM: arm64: vgic-v3: Add ICV_BPR0_EL1 handler

Add a handler for reading/writing the guest's view of the ICC_BPR0_EL1
register, which is located in the ICH_VMCR_EL2.BPR0 field.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 0ce7f81..6b80211 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -180,6 +180,7 @@
 
 #define SYS_VBAR_EL1			sys_reg(3, 0, 12, 0, 0)
 
+#define SYS_ICC_BPR0_EL1		sys_reg(3, 0, 12, 8, 3)
 #define SYS_ICC_AP1Rn_EL1(n)		sys_reg(3, 0, 12, 9, n)
 #define SYS_ICC_DIR_EL1			sys_reg(3, 0, 12, 11, 1)
 #define SYS_ICC_SGI1R_EL1		sys_reg(3, 0, 12, 11, 5)