thermal: Use dev_fwnode()

thermal: Use dev_fwnode()

irq_domain_create_simple() takes fwnode as the first argument. It can be
extracted from the struct device using dev_fwnode() helper instead of
using of_node with of_fwnode_handle().

So use the dev_fwnode() helper.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Amit Kucheria <amitk@kernel.org>
Cc: Thara Gopinath <thara.gopinath@gmail.com>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Lukasz Luba <lukasz.luba@arm.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-tegra@vger.kernel.org
Link: https://lore.kernel.org/r/20250611104348.192092-20-jirislaby@kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>