baseboard-kukui: always build firmware on firmware branch

Ensure developers with public overlay can build firmware properly
(without this, emerge-jacuzzi chromeos-bootimage will not have
 EC RW hash).

BUG=None
TEST=None

Change-Id: Ib53c982b3aead6f688c487533a65e421de5c5ac7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/board-overlays/+/2227660
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Commit-Queue: Hung-Te Lin <hungte@chromium.org>
Tested-by: Hung-Te Lin <hungte@chromium.org>
Auto-Submit: Hung-Te Lin <hungte@chromium.org>
diff --git a/baseboard-kukui/profiles/base/make.defaults b/baseboard-kukui/profiles/base/make.defaults
index 761e4f6..26c0db5 100644
--- a/baseboard-kukui/profiles/base/make.defaults
+++ b/baseboard-kukui/profiles/base/make.defaults
@@ -40,3 +40,6 @@
 
 # Google USBPD peripheral firmwares
 LINUX_FIRMWARE="${LINUX_FIRMWARE} cros-pd"
+
+# For firmwarae branch, always build firmware.
+USE="${USE} cros_ec bootimage"
diff --git a/overlay-kukui/profiles/base/make.defaults b/overlay-kukui/profiles/base/make.defaults
index 916f568..4d22e88 100644
--- a/overlay-kukui/profiles/base/make.defaults
+++ b/overlay-kukui/profiles/base/make.defaults
@@ -7,8 +7,6 @@
 
 USE="${USE} kukui"
 
-USE="${USE} bootimage"
-
 USE="${USE} detachable_ui"
 
 USE="${USE} als"
@@ -16,9 +14,6 @@
 # Enable unibuild
 USE="${USE} unibuild"
 
-# Building EC
-USE="${USE} cros_ec"
-
 USE="${USE} touch_centric_device"
 
 EC_FIRMWARE="kukui"