input: Allow repeat filtering to be disabled

input: Allow repeat filtering to be disabled

Generally the input library handles processing of a list of scanned keys.
Repeated keys need to be generated based on a timer in this case, since all
that is provided is a list of keys current depressed.

Keyboards which do their own scanning will resend codes when they want to
inject a repeating key. Provide a function which tells the input library to
accept repeating keys and not to try to second-guess the caller.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>