pmdomain: core: Add missing put_device()

When removing a genpd we don't clean up the genpd->dev correctly. Let's add
the missing put_device() in genpd_free_data() to fix this.

Fixes: 401ea157 ("PM / Domain: Add struct device to genpd")
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Message-ID: <20241122134207.157283-2-ulf.hansson@linaro.org>