atlas_ish: enable firmware build

this turns on the atlas_ish firmware build as part of the regular EC
firmware build.

BUG=b:117129410
BRANCH=none
TEST=verified on stabilize-atlas-11177 branch that we can turn on the
	ISH firmware build

Change-Id: I11d4e8f83d8fe702a915ec853ef5765f889d88f6
Signed-off-by: Caveh Jalali <caveh@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/1298401
Reviewed-by: Caveh Jalali <caveh@google.com>
Commit-Queue: Caveh Jalali <caveh@google.com>
Tested-by: Caveh Jalali <caveh@google.com>
diff --git a/overlay-atlas/profiles/base/make.defaults b/overlay-atlas/profiles/base/make.defaults
index d15050f..96e95e2 100644
--- a/overlay-atlas/profiles/base/make.defaults
+++ b/overlay-atlas/profiles/base/make.defaults
@@ -27,6 +27,7 @@
 
 # All firmware to build from the EC code base.
 EC_FIRMWARE="atlas"
+EC_FIRMWARE_EXTRA="atlas_ish"
 
 # iwlwifi firmware for ThunderPeak2/1216 chip.
 LINUX_FIRMWARE="${LINUX_FIRMWARE} iwlwifi-9260"