pei_data.h: Fix comment

I added a comment to the pei_data.h to remind users about
how the OC pins are mapped.

Change-Id: I4d74eb69fc78816a69e61260c2c9b2b3e58cafec
Signed-off-by: Marc Jones <marc.jones@se-eng.com>
Reviewed-on: http://review.coreboot.org/1824
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martin@se-eng.com>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/src/northbridge/intel/sandybridge/pei_data.h b/src/northbridge/intel/sandybridge/pei_data.h
index 5bb3b38..34adddc 100644
--- a/src/northbridge/intel/sandybridge/pei_data.h
+++ b/src/northbridge/intel/sandybridge/pei_data.h
@@ -79,6 +79,9 @@
 	 *  [1] = overcurrent pin
 	 *  [2] = length
 	 *
+	 * Ports 0-7 can be mapped to OC0-OC3
+	 * Ports 8-13 can be mapped to OC4-OC7
+	 *
 	 * Port Length
 	 *  MOBILE:
 	 *   < 0x050 = Setting 1 (back panel, 1-5in, lowest tx amplitude)