Input: adp5589 - remove a leftover header file

Input: adp5589 - remove a leftover header file

In commit 3bdbd0858df6 ("Input: adp5589: remove the driver") the last user
of include/linux/input/adp5589.h was removed along with the whole driver,
thus the header file can be also removed.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Fixes: 3bdbd0858df6 ("Input: adp5589: remove the driver")
Link: https://patch.msgid.link/20260113151140.3843753-1-vz@mleia.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>