iio: light: isl29018: drop ACPI_PTR() and CONFIG_ACPI guards

iio: light: isl29018: drop ACPI_PTR() and CONFIG_ACPI guards

The complexity of config guards needed for ACPI_PTR() is not worthwhile
for the small amount of saved data. This example was doing it correctly
but I am proposing dropping this so as to reduce chance of cut and paste
where it is done wrong.  Also drop now unneeded linux/acpi.h include and
added linux/mod_devicetable.h for struct acpi_device_id definition.

Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20241024191200.229894-22-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>