soc/intel/skylake: Split AC/DC settings for Deep Sx config

Currently when enabling Deep S3 or Deep S5 it unconditionally gets enabled
in both DC and AC states.  However since using Deep S3 disables some
expected features like wake-on-USB it is not always desired to enable the
same state in both modes.

To address this split the setting and add a separate config for Deep Sx in
AC and DC states.

All motherboards that set this config were updated, but there is no actual
change in behavior in this commit.

BUG=b:36723679
BRANCH=none
TEST=This commit has no runtime visible changes, I verified on Eve that the
Deep SX config registers are unchanged, and it compiles for all affected boards.

Change-Id: I590f145847785b5a7687f235304e988888fcea8a
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://review.coreboot.org/19239
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
diff --git a/src/mainboard/intel/kunimitsu/devicetree.cb b/src/mainboard/intel/kunimitsu/devicetree.cb
index 11cb31a..17e8e27 100644
--- a/src/mainboard/intel/kunimitsu/devicetree.cb
+++ b/src/mainboard/intel/kunimitsu/devicetree.cb
@@ -1,7 +1,8 @@
 chip soc/intel/skylake
 
 	# Enable deep Sx states
-	register "deep_s5_enable" = "1"
+	register "deep_s5_enable_ac" = "1"
+	register "deep_s5_enable_dc" = "1"
 	register "deep_sx_config" = "DSX_EN_LAN_WAKE_PIN"
 
 	# GPE configuration