Revert "gpio_keys: fix typo during flip_powerkey registration"

This reverts commit f974ac0d2eeda1065a60e83cfd1abba30e5a0321.
Revert "gpio_keys: return early when flip_cover == gpio_flip_cover"

This reverts commit 50910f848c300f54a4e21b9d4c46823683e8d1d2.
Revert "gpio_keys: fix registration order"

This reverts commit f272f92fcf100c9e30b81ae26eff3c4c2f41caf5.