Each call to device/fwnode_get_named_child_node() must be matched
with a call to fwnode_handle_put() once the corresponding node is
no longer in use. This ensures a reference count remains balanced
in the case of dynamic device tree support.

Currently, the driver does not call fwnode_handle_put() on nested
event nodes. This patch solves this problem by adding the missing
instances of fwnode_handle_put().

As part of this change, the logic which parses each channel's key
code is gently refactored in order to reduce the number of places
from which fwnode_handle_put() is called.

Fixes: 04e49867 ("Input: add support for Azoteq IQS269A")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/Y7Rsx68k/gvDVXAt@nixie71Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>