There is a general move towards the use of dev_pm_ops rather than
bus specific suspend APIs as this simplifies both the bus and PM core
implementations. Convert the eeti_ts driver over.

Compile tested only by me, but Sven Neumann reports that the new code
works.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Tested-by: Sven Neumann <s.neumann@raumfeld.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>