eeprom: at24: Drop of_match_ptr() and ACPI_PTR() protections

eeprom: at24: Drop of_match_ptr() and ACPI_PTR() protections

These result in a very small reduction in driver size, but at the cost
of more complex build and slightly harder to read code. In the case of
of_match_ptr() it also prevents use of PRP0001 ACPI based identification.
In this particular case we have a valid ACPI/PNP ID that should be used
in preference to PRP0001 but doesn't mean we should prevent that route.

With this done, drop unneeded of*.h inclusions and __maybe_unused markers.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20250225100838.362125-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>