drivers/ec/cros/ec: Export the helper function to get main EC handle

BUG=None
BRANCH=None
TEST=Boot to ChromeOS.

Change-Id: I81068857f3690ec884868d2a633f21c0ea4ee8fa
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/depthcharge/+/1661010
Tested-by: Karthikeyan Ramasubramanian <kramasub@chromium.org>
Commit-Queue: Karthikeyan Ramasubramanian <kramasub@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
2 files changed