ahci: add support for IBM Akebono platform device

The new IBM Akebono board has a PPC476GTR SoC with an AHCI compliant
SATA controller. This patch adds a compatible property for the new SoC
to the AHCI platform driver.
Signed-off-by: NAlistair Popple <alistair@popple.id.au>
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org

drivers/ata/ahci_platform.c

@@ -329,6 +329,7 @@ static SIMPLE_DEV_PM_OPS(ahci_pm_ops, ahci_suspend, ahci_resume);
 static const struct of_device_id ahci_of_match[] = {
 	{ .compatible = "snps,spear-ahci", },
 	{ .compatible = "snps,exynos5440-ahci", },
+	{ .compatible = "ibm,476gtr-ahci", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, ahci_of_match);