ARM: KVM: Implement HVC_GET_VECTORS in the init code

Now that we have an infrastructure to handle hypercalls in the KVM
init code, let's implement HVC_GET_VECTORS there.
Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>

arch/arm/kvm/init.S

@@ -122,7 +122,12 @@ __do_hyp_init:
 	eret
 
 ENTRY(__kvm_handle_stub_hvc)
-	cmp	r0, #HVC_RESET_VECTORS
+	cmp	r0, #HVC_GET_VECTORS
+	bne	1f
+	mrc	p15, 4, r0, c12, c0, 0	@ get HVBAR
+	b	exit
+
+1:	cmp	r0, #HVC_RESET_VECTORS
 	bne	1f
 ENTRY(__kvm_hyp_reset)
 	/* We're now in idmap, disable MMU */