Input: edt-ft5x06 - move parameter restore into helper

Input: edt-ft5x06 - move parameter restore into helper

We need to restore the parameters if we switch between the
factory/work mode and during the resume process if we switched off the
power-supply. Therefore refactor edt_ft5x06_work_mode() and move the
"restore the parameters" into a helper routine so we can reuse it later.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Link: https://lore.kernel.org/r/20200227112819.16754-3-m.felsch@pengutronix.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>