fpga: dfl: store platform device name in feature device data

fpga: dfl: store platform device name in feature device data

Add a new member, pdev_name, to the structure dfl_feature_dev_data that
holds the platform device name for convenience. A subsequent commit will
completely destroy the platform device during port release, after which
fdata->dev is unavailable, while fdata itself remains available.

Signed-off-by: Peter Colberg <peter.colberg@intel.com>
Reviewed-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Reviewed-by: Basheer Ahmed Muddebihal <basheer.ahmed.muddebihal@linux.intel.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20241120011035.230574-14-peter.colberg@intel.com
Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>