pinctrl: at91: Use dev_err_probe() instead of custom messaging

pinctrl: at91: Use dev_err_probe() instead of custom messaging

The custom message has no value except printing the error code,
the same does dev_err_probe(). Let's use the latter for the sake
of unification.

Note that some APIs already have messaging in them and some simply
do not require the current noise.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20230215134242.37618-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>