skylake mainboards: Enable CONFIG_VBOOT_EC_SLOW_UPDATE

Updating EC+PD takes long enough to update that it is good to
show the "critical update" screen when doing an EC/PD update.

BUG=chrome-os-partner:49650
BRANCH=glados
TEST=Build and boot on chell in normal mode with an EC update payload
and ensure that it reboots to enable graphics, shows the "critical
update" screen, and then reboots to disable graphics init again.

Change-Id: I436b96b95595b68273e594bdcfe2db0789ee26b2
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 08e45decd066f8f57ad103ff8b76cb7a916afa9e
Original-Change-Id: Ie250f4531437e4a0ce14b5aeb0fe564e9461fe4d
Original-Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/322783
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/13075
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/mainboard/google/chell/Kconfig

@@ -24,6 +24,7 @@ config CHROMEOS
 	select CHROMEOS_VBNV_CMOS
 	select EC_SOFTWARE_SYNC
 	select LID_SWITCH
+	select VBOOT_EC_SLOW_UPDATE
 	select VBOOT_OPROM_MATTERS
 	select VIRTUAL_DEV_SWITCH
 

src/mainboard/google/glados/Kconfig

@@ -24,6 +24,7 @@ config CHROMEOS
 	select CHROMEOS_VBNV_CMOS
 	select EC_SOFTWARE_SYNC
 	select LID_SWITCH
+	select VBOOT_EC_SLOW_UPDATE
 	select VBOOT_OPROM_MATTERS
 	select VIRTUAL_DEV_SWITCH
 

src/mainboard/google/lars/Kconfig

@@ -24,6 +24,7 @@ config CHROMEOS
 	select CHROMEOS_RAMOOPS_DYNAMIC
 	select CHROMEOS_VBNV_CMOS
 	select LID_SWITCH
+	select VBOOT_EC_SLOW_UPDATE
 	select VBOOT_OPROM_MATTERS
 	select VIRTUAL_DEV_SWITCH
 	select EC_SOFTWARE_SYNC

src/mainboard/intel/kunimitsu/Kconfig

@@ -23,6 +23,7 @@ config CHROMEOS
 	select CHROMEOS_RAMOOPS_DYNAMIC
 	select CHROMEOS_VBNV_CMOS
 	select LID_SWITCH
+	select VBOOT_EC_SLOW_UPDATE
 	select VBOOT_OPROM_MATTERS
 	select VIRTUAL_DEV_SWITCH
 	select EC_SOFTWARE_SYNC