new_variant_fulltest: Fix 207786a0 ("new_variant: Add support...")

The mentioned commit broke new_variant_fulltest for everything non-brya0
by using a separate firmware target for depthcharge. Instead, make this
explicit and only use the separate target for brya0.

BUG=b:193527706
TEST=new_variant_fulltest.sh volteer2 passes
new_variant_fulltest.sh brya0 passes

Change-Id: I7ddae05bd6d396bbea46b1d4012105cc83cc0f6e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/3089774
Tested-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>
Commit-Queue: Paul Fagerburg <pfagerburg@chromium.org>
1 file changed