When unlocking an encrypted disk with a TKey we need a few more UI
operations:
- allow the password-entry textline to be shown/hidden
- allow showing instructions to the user, as well as unlock result
- obtain the password entered by the user
Add these to the API and implement them in the multi UI.
Signed-off-by: Simon Glass <simon.glass@canonical.com>
All UI implementations will likely share a number of common elements, so
move these into a per-device uclass struct.
Signed-off-by: Simon Glass <sjg@chromium.org>
