x86/mce: Streamline MCE subsystem's naming

Rename the containing folder to "mce" which is the most widespread name.
Drop the "mce[-_]" filename prefix of some compilation units (while
others don't have it).

This unifies the file naming in the MCE subsystem:

mce/
|-- amd.c
|-- apei.c
|-- core.c
|-- dev-mcelog.c
|-- genpool.c
|-- inject.c
|-- intel.c
|-- internal.h
|-- Makefile
|-- p5.c
|-- severity.c
|-- therm_throt.c
|-- threshold.c
`-- winchip.c

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20181205141323.14995-1-bp@alien8.de

arch/x86/kernel/cpu/mce/threshold.c

@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Common corrected MCE threshold handler code:
+ */
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+
+#include <asm/irq_vectors.h>
+#include <asm/apic.h>
+#include <asm/mce.h>
+#include <asm/trace/irq_vectors.h>
+
+static void default_threshold_interrupt(void)
+{
+	pr_err("Unexpected threshold interrupt at vector %x\n",
+		THRESHOLD_APIC_VECTOR);
+}
+
+void (*mce_threshold_vector)(void) = default_threshold_interrupt;
+
+asmlinkage __visible void __irq_entry smp_threshold_interrupt(void)
+{
+	entering_irq();
+	trace_threshold_apic_entry(THRESHOLD_APIC_VECTOR);
+	inc_irq_stat(irq_threshold_count);
+	mce_threshold_vector();
+	trace_threshold_apic_exit(THRESHOLD_APIC_VECTOR);
+	exiting_ack_irq();
+}