mb/google/poppy: Update PL2 settings

Update PL2 override setting to 15W as per KBL Power Arch Guide.

Change-Id: I4a6f875f8c3bdb012d6ff97c1429f32db5210893
Signed-off-by: Sumeet Pawnikar <sumeet.r.pawnikar@intel.com>
Reviewed-on: https://review.coreboot.org/20943
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
diff --git a/src/mainboard/google/poppy/variants/soraka/devicetree.cb b/src/mainboard/google/poppy/variants/soraka/devicetree.cb
index 3de9854..b874093 100644
--- a/src/mainboard/google/poppy/variants/soraka/devicetree.cb
+++ b/src/mainboard/google/poppy/variants/soraka/devicetree.cb
@@ -201,7 +201,8 @@
 	}"
 
 	register "speed_shift_enable" = "1"
-	register "tdp_pl2_override" = "7"
+	# PL2 override 15W for KBL-Y
+	register "tdp_pl2_override" = "15"
 	register "tcc_offset" = "10"     # TCC of 90C
 
 	# Use default SD card detect GPIO configuration