x86: Geode MFGPT clock event device support

Add support for an MFGPT clock event device; this allows us to use MFGPTs as
the basis for high-resolution timers.

Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 2128de6..f27cdd7 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1009,6 +1009,10 @@
 	meye.*=		[HW] Set MotionEye Camera parameters
 			See Documentation/video4linux/meye.txt.
 
+	mfgpt_irq=	[IA-32] Specify the IRQ to use for the
+			Multi-Function General Purpose Timers on AMD Geode
+			platforms.
+
 	mga=		[HW,DRM]
 
 	mousedev.tap_time=