Pit: set PWM to external on Parade

The PWM is controlled externally from the APU.

Change-Id: Ia5130d7616991a78dfde44043a60a32cee4f145c
Signed-off-by: Ronald G. Minnich <rminnich@google.com>
Reviewed-on: https://gerrit.chromium.org/gerrit/61513
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Commit-Queue: Ronald G. Minnich <rminnich@chromium.org>
Tested-by: Ronald G. Minnich <rminnich@chromium.org>
Reviewed-on: http://review.coreboot.org/4363
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
diff --git a/src/mainboard/google/pit/mainboard.c b/src/mainboard/google/pit/mainboard.c
index 515424a..3f04eec 100644
--- a/src/mainboard/google/pit/mainboard.c
+++ b/src/mainboard/google/pit/mainboard.c
@@ -146,13 +146,8 @@
 	{ 0x01, 0xca, 0x01 },
 	 /* DPCD40B, Initial Code minor revision '05' */
 	{ 0x01, 0xcb, 0x05 },
-	 /* DPCD720, Select internal PWM */
-	{ 0x01, 0xa5, 0xa0 },
-	 /*
-	  * FFh for 100% PWM of brightness, 0h for 0%
-	  * brightness
-	  */
-	{ 0x01, 0xa7, 0xff },
+	 /* DPCD720, Select external PWM */
+	{ 0x01, 0xa5, 0x80 },
 	 /*
 	  * Set LVDS output as 6bit-VESA mapping,
 	  * single LVDS channel