pinctrl: stm32: use dynamic allocation of GPIO base

Since commit 502df79b ("gpiolib: Warn on drivers still using static
gpiobase allocation"), one or more warnings are printed during boot on
systems where static allocation of GPIO base is used:

[    0.197707] gpio gpiochip0: Static allocation of GPIO base is deprecated, use dynamic allocation.
[    0.199942] stm32f429-pinctrl soc:pinctrl@40020000: GPIOA bank added
[    0.200711] gpio gpiochip1: Static allocation of GPIO base is deprecated, use dynamic allocation.
[    0.202855] stm32f429-pinctrl soc:pinctrl@40020000: GPIOB bank added
[    0.203591] gpio gpiochip2: Static allocation of GPIO base is deprecated, use dynamic allocation.
[    0.205704] stm32f429-pinctrl soc:pinctrl@40020000: GPIOC bank added
[    0.206338] gpio gpiochip3: Static allocation of GPIO base is deprecated, use dynamic allocation.
[    0.208448] stm32f429-pinctrl soc:pinctrl@40020000: GPIOD bank added
[    0.209182] gpio gpiochip4: Static allocation of GPIO base is deprecated, use dynamic allocation.
[    0.211282] stm32f429-pinctrl soc:pinctrl@40020000: GPIOE bank added
[    0.212094] gpio gpiochip5: Static allocation of GPIO base is deprecated, use dynamic allocation.
[    0.214270] stm32f429-pinctrl soc:pinctrl@40020000: GPIOF bank added
[    0.215005] gpio gpiochip6: Static allocation of GPIO base is deprecated, use dynamic allocation.
[    0.217110] stm32f429-pinctrl soc:pinctrl@40020000: GPIOG bank added
[    0.217845] gpio gpiochip7: Static allocation of GPIO base is deprecated, use dynamic allocation.
[    0.219959] stm32f429-pinctrl soc:pinctrl@40020000: GPIOH bank added
[    0.220602] gpio gpiochip8: Static allocation of GPIO base is deprecated, use dynamic allocation.
[    0.222714] stm32f429-pinctrl soc:pinctrl@40020000: GPIOI bank added
[    0.223483] gpio gpiochip9: Static allocation of GPIO base is deprecated, use dynamic allocation.
[    0.225594] stm32f429-pinctrl soc:pinctrl@40020000: GPIOJ bank added
[    0.226336] gpio gpiochip10: Static allocation of GPIO base is deprecated, use dynamic allocation.
[    0.228490] stm32f429-pinctrl soc:pinctrl@40020000: GPIOK bank added

So let's follow the suggestion and use dynamic allocation.

Tested on STM32F429I-DISC1 board.
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Link: https://lore.kernel.org/r/20230227205131.2104082-1-dario.binacchi@amarulasolutions.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/stm32/pinctrl-stm32.c

@@ -1330,7 +1330,7 @@ static int stm32_gpiolib_register_bank(struct stm32_pinctrl *pctl, struct fwnode
 	if (fwnode_property_read_u32(fwnode, "st,bank-ioport", &bank_ioport_nr))
 		bank_ioport_nr = bank_nr;
 
-	bank->gpio_chip.base = bank_nr * STM32_GPIO_PINS_PER_BANK;
+	bank->gpio_chip.base = -1;
 
 	bank->gpio_chip.ngpio = npins;
 	bank->gpio_chip.fwnode = fwnode;