Input: ad714x - allow platform code to specify irqflags

Add option to specify irqflags in platfrom data.
Also update copyright notice.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Tested-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>