ACPI / spi: attach GPIO IRQ from ACPI description to SPI device

spi->irq was ignoring GpioInt property setting it to -1.
acpi_dev_gpio_irq_get returns and configure the slave IRQ according to
the ACPI slave node description.

It is now inline with devicetree behavior.
Acked-by: NMark Brown <broonie@kernel.org>
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/spi/spi.c

@@ -1623,6 +1623,9 @@ static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
 		return AE_OK;
 	}
 
+	if (spi->irq < 0)
+		spi->irq = acpi_dev_gpio_irq_get(adev, 0);
+
 	adev->power.flags.ignore_parent = true;
 	strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias));
 	if (spi_add_device(spi)) {