Remove unused terminalPrivate.getCroshSettings

Function getCroshSettings was only required during terminal SWA
migration which is now complete.

TBR=michaelpg@chromium.org

Change-Id: I087ef9f7e6b32a10b8023bb12770666143b78ca7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2345931


Commit-Queue: Joel Hockey <joelhockey@chromium.org>
Reviewed-by: Jason Lin <lxj@google.com>
Reviewed-by: Ben Wells <benwells@chromium.org>
Cr-Commit-Position: refs/heads/master@{#796712}