accessibility: speakup: phonetic spelling while arrowing letter by letter

This patch includes an enhancement requested frequently on the mailing
list.[1][2] It adds a variable, cur_phonetic in the spk_vars, which can
be set as a module parameter, as well as in /sys/speakup/cur_phonetic.
This patch also documents cur_phonetic as a sysfs attribute in
sysfs-driver-speakup.

When cur_phonetic=1, it causes speakup to speak letters phonetically if
paused on the character while arrowing through a word.

When a user does not set cur_phonetic to any value, the default value
for it would be 0.

[1]: https://github.com/linux-speakup/speakup/issues/6
[2]: https://github.com/linux-speakup/speakup/issues/5

since V1:
- removed unnecessary lines

Signed-off-by: Mushahid Hussain<mushi.shar@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Link: https://lore.kernel.org/r/20221115100530.91174-3-mushi.shar@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

speakup: Notify synthesizers of the punctuation level change

Even if speakup does the filtering itself, it does not filter out A_PUNC
characters (because these are needed e.g. for prosody), so we have to tell
synthesizers whether they should filter them out or not.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Link: https://lore.kernel.org/r/20220823222515.412752202@ens-lyon.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

speakup: Make dectlk flush timeout configurable

In case the serial port or cable got faulty, we may not be getting
acknowledgements any more. The driver then currently waits for 4s to
avoid jamming the device. This makes this delay configurable.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Link: https://lore.kernel.org/r/20210128180116.1848120-3-samuel.thibault@ens-lyon.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging/speakup: Move out of staging

The nasty TODO items are done.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Link: https://lore.kernel.org/r/20200729003531.907370-1-samuel.thibault@ens-lyon.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>