hwmon: (coretemp) Remove redundant temp_data->is_pkg_data

temp_data->index saves the index in pdata->core_data[]. It is not used
by package temp_data.

Use temp_data->index as the indicator of package temp_data and remove
redundant temp_data->is_pkg_data.

No functional change.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20240202092144.71180-11-rui.zhang@intel.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>