Ulf Hansson [off-list ref] writes:

The reference counting isn't needed, let's remove it.

After reading the commit that added this feature[1], I think this
changelog needs a more detail explaining why it's not needed anymore.

Kevin

[1]
commit 1d5fcfec22ce5f69db0d29284d2b65ff8ab1bfaa
Author: Rafael J. Wysocki [off-list ref]
Date:   Thu Jul 5 22:12:32 2012 +0200

    PM / Domains: Add device domain data reference counter

    Add a mechanism for counting references to the
    struct generic_pm_domain_data object pointed to by
    dev->power.subsys_data->domain_data if the device in question
    belongs to a generic PM domain.

    This change is necessary for a subsequent patch making it possible to
    allocate that object from within pm_genpd_add_callbacks(), so that
    drivers can attach their PM domain device callbacks to devices before
    those devices are added to PM domains.

    This patch has been tested on the SH7372 Mackerel board.

    Signed-off-by: Rafael J. Wysocki [off-list ref]