kalista: disable debug serial console

BUG=b:122567422
TEST=1. build pass
     2. no console log output

Change-Id: Ie5b20e49635a4f592970828a14138b384e361f3b
Reviewed-on: https://chromium-review.googlesource.com/1401890
Commit-Ready: Zhuohao Lee <zhuohao@chromium.org>
Tested-by: Zhuohao Lee <zhuohao@chromium.org>
Reviewed-by: YH Lin <yueherngl@chromium.org>
(cherry picked from commit 8b5fd71e83d7a60ec5fb06acf93f4aa6e3f4cc0c)
Reviewed-on: https://chromium-review.googlesource.com/c/1411934
Commit-Queue: Zhuohao Lee <zhuohao@chromium.org>
Reviewed-by: Zhuohao Lee <zhuohao@chromium.org>
diff --git a/overlay-kalista/profiles/base/make.defaults b/overlay-kalista/profiles/base/make.defaults
index f9fe6bf..2b38cbc 100644
--- a/overlay-kalista/profiles/base/make.defaults
+++ b/overlay-kalista/profiles/base/make.defaults
@@ -10,5 +10,5 @@
 USE="${USE} unibuild"
 
 # Uncomment these lines to activate the serial port.
-TTY_CONSOLE="ttyS0"
-USE="${USE} pcserial"
+# TTY_CONSOLE="ttyS0"
+# USE="${USE} pcserial"