thermal: intel: int340x: processor_thermal_device: simplify to get driver data

This simplifies getting the 'driver_data' from 'struct device' directly.
Going through platform_device or pci_dev is not required. Also removes
condition check as the private data stored with dev pointer, means
irrespective of enumeration mode, we can use dev_get_drvdata().
This removes the unnecessary step back and forth.

Signed-off-by: Sumeet Pawnikar <sumeet.r.pawnikar@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>