iio: adc: at91_adc: add Kconfig dep on the OF symbol and remove of_match_ptr()

This tries to solve a warning reported by the lkp bot:

>> drivers/iio/adc/at91_adc.c:1439:34: warning: unused variable
>> 'at91_adc_dt_ids' [-Wunused-const-variable]
   static const struct of_device_id at91_adc_dt_ids[] = {
                                    ^
   1 warning generated.

This warning has appeared after the AT91_ADC driver compilation has been
enabled via the COMPILE_TEST symbol dependency.

The warning is caused by the 'of_match_ptr()' helper which returns NULL if
OF is undefined. This driver should build only for device-tree context, so
a dependency on the OF Kconfig symbol has been added.
Also, the usage of of_match_ptr() helper has been removed since it
shouldn't ever return NULL (because the driver should not be built for the
non-OF context).

Fixes: 4027860dcc4c ("iio: Kconfig: at91_adc: add COMPILE_TEST dependency to driver")
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Alexandru Ardelean <[email protected]>
Reviewed-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jonathan Cameron <[email protected]>

0 files changed, 0 insertions, 0 deletions