TTY/ASoC: Rename N_AMSDELTA line discipline to N_V253

The patch changes the line discipline name registered in include/linux/tty.h
and updates the ams-delta machine driver to use it.

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>