pinctrl: sunxi: Add some defensiveness for regulators array

The sunxi pinctrl has a fixed size array it uses to store regulators used
in the driver. There is currently nothing that ensures that the number of
elements in the array is large enough to map the regulators defined by the
individual SoCs. While this is currently the case having an explicit check
in there will make life easier for anyone debugging memory issues that
manifest in the driver so let's add one.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20230712-pinctrl-sunxi-boudns-v1-1-85f37de79b9f@kernel.org


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>