powerpc/64s: Enhance the information in cpu_show_spectre_v1()

We now have barrier_nospec as mitigation so print it in
cpu_show_spectre_v1() when enabled.
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/security.c

@@ -120,6 +120,9 @@ ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr, c
 	if (!security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR))
 		return sprintf(buf, "Not affected\n");
 
+	if (barrier_nospec_enabled)
+		return sprintf(buf, "Mitigation: __user pointer sanitization\n");
+
 	return sprintf(buf, "Vulnerable\n");
 }