autotest: Remove custom_recovery_mode from servo

It is a legacy method. No one uses it now.

BUG=None
TEST=Checked autotest and hdctools repos. No one uses this method.

Change-Id: I70e793715403d91842a0897c6c19876d8df9365b
Reviewed-on: https://chromium-review.googlesource.com/267291
Reviewed-by: Yusuf Mohsinally <mohsinally@chromium.org>
Commit-Queue: Tom Tam <waihong@google.com>
Tested-by: Tom Tam <waihong@google.com>
1 file changed