spi: Add TODO comment about ACPI GPIO setup

Add a TODO comment that ideally the ACPI/gpiolib core code should take care
of setting GPIO direction and/or bias according to ACPI GPIO resources.

If this TODO gets implemented then the acpi_dev_gpio_irq_get() call in
acpi_register_spi_device() can be dropped.

Suggested-by: Andy Shevchenko <[e-mail]>
Signed-off-by: Hans de Goede <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/spi/spi.c

···
 	 * here too, because this call sets the GPIO direction and/or bias.
 	 * Setting these needs to be done even if there is no driver, in which
 	 * case spi_probe() will never get called.
+	 * TODO: ideally the setup of the GPIO should be handled in a generic
+	 * manner in the ACPI/gpiolib core code.
 	 */
 	if (spi->irq < 0)
 		spi->irq = acpi_dev_gpio_irq_get(adev, 0);