x86/feature: Report presence of IBPB and IBRS control

CVE-2017-5715 (Spectre v2 Intel)

Report presence of IBPB and IBRS.
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
(backported from commit e6941d30960ab43adfa0bbb446e73036bfb52842)
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

arch/x86/kernel/cpu/intel.c

@@ -528,6 +528,11 @@ static void init_intel(struct cpuinfo_x86 *c)
 		detect_vmx_virtcap(c);
 
 	init_intel_energy_perf(c);
+
+	if (boot_cpu_has(X86_FEATURE_SPEC_CTRL))
+                printk_once(KERN_INFO "FEATURE SPEC_CTRL Present\n");
+        else
+                printk_once(KERN_INFO "FEATURE SPEC_CTRL Not Present\n");
 }
 
 #ifdef CONFIG_X86_32