gpio: rdc321x: Convert PCIBIOS_* return codes to errnos

rdc_gpio_config() uses pci_{read,write}_config_dword() that return
PCIBIOS_* codes. rdc_gpio_config() is used for
direction_{input,output}() in the struct gpio_chip which both require
normal errnos to be returned.

Similarly, rdc321x_gpio_probe() that is probe function returns
PCIBIOS_* codes without converting them first into normal errnos.

Convert PCIBIOS_* returns code using pcibios_err_to_errno() into normal
errno before returning them to fix both issues.

Signed-off-by: Ilpo Järvinen <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Bartosz Golaszewski <[e-mail]>

drivers/gpio/gpio-rdc321x.c

···
 unlock:
 	spin_unlock(&gpch->lock);
 
-	return err;
+	return pcibios_err_to_errno(err);
 }
 
 /* configure GPIO pin as input */
···
 					rdc321x_gpio_dev->reg1_data_base,
 					&rdc321x_gpio_dev->data_reg[0]);
 	if (err)
-		return err;
+		return pcibios_err_to_errno(err);
 
 	err = pci_read_config_dword(rdc321x_gpio_dev->sb_pdev,
 					rdc321x_gpio_dev->reg2_data_base,
 					&rdc321x_gpio_dev->data_reg[1]);
 	if (err)
-		return err;
+		return pcibios_err_to_errno(err);
 
 	dev_info(&pdev->dev, "registering %d GPIOs\n",
 					rdc321x_gpio_dev->chip.ngpio);