new_variant: remove EC_BUILDALL step

The upload hook for buildall has been removed as of CL:2436379, so
calling `make buildall -j` as part of the new variant process is
unnecessary.

BUG=b:173801263
TEST=run `new_variant_fulltest.sh` for hatch, trembyle, volteer, and
waddledee, and verify that they are successful.

Cq-Depend: chromium:2436379
Change-Id: I204cf2909b599d917c6fd5fe73ea02b0973fb2c9
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/2552717
Tested-by: Paul Fagerburg <pfagerburg@chromium.org>
Commit-Queue: Paul Fagerburg <pfagerburg@chromium.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
5 files changed