platform/x86: ideapad-laptop: use for_each_set_bit() helper to simplify event processing

platform/x86: ideapad-laptop: use for_each_set_bit() helper to simplify event processing

The current code used the combination of a for loop + test_bit,
which can be simplified using for_each_set_bit(), so utilize that.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210203215403.290792-10-pobrn@protonmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>