gpio: shared: handle pins shared by child nodes of devices

gpio: shared: handle pins shared by child nodes of devices

Shared GPIOs may be assigned to child nodes of device nodes which don't
themselves bind to any struct device. We need to pass the firmware node
that is the actual consumer to gpiolib-shared and compare against it
instead of unconditionally using the fwnode of the consumer device.

Fixes: a060b8c511ab ("gpiolib: implement low-level, shared GPIO support")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Closes: https://lore.kernel.org/all/921ba8ce-b18e-4a99-966d-c763d22081e2@nvidia.com/
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://patch.msgid.link/20260318-gpio-shared-xlate-v2-2-0ce34c707e81@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>