docs: hwmon: (coretemp) fix outdated documentation

docs: hwmon: (coretemp) fix outdated documentation

- Remove broken Intel wiki link; add Intel SDM download page link
- Fix description of tempX_max to clarify it is not Core2-only
- Correct tempX_label string for package temperature (changed in commit
2bc0e6d07ee5 ("hwmon: (coretemp) rearrange tjmax handing code"))

Signed-off-by: Roman Bakshansky <bakshansky.lists@gmail.com>
Link: https://lore.kernel.org/r/20260517152027.350356-1-bakshansky.lists@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>