x86, cpu: Convert AMD Erratum 400

Convert AMD erratum 400 to the bug infrastructure. Then, retract all
exports for modules since they're not needed now and make the AMD
erratum checking machinery local to amd.c. Use forward declarations to
avoid shuffling too much code around needlessly.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1363788448-31325-7-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 14ae100..e718f15 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -495,7 +495,7 @@
 	if (x86_idle)
 		return;
 
-	if (cpu_has_amd_erratum(amd_erratum_400)) {
+	if (cpu_has_bug(c, X86_BUG_AMD_APIC_C1E)) {
 		/* E400: APIC timer interrupt does not wake up CPU from C1e */
 		pr_info("using AMD E400 aware idle routine\n");
 		x86_idle = amd_e400_idle;