sunxi: ahci: Add a delay after enabling target power

If the target power is connected through a gpio, then give the target some
time to power up before continuing with ahci / sata probing, this avoids
link timeouts, without penalizing other boards where there is no target
power gpio.

Why 500 ms ? I started with 200, that was not enough, then I went to 500 which
worked, lowering it to 350 broke things again, so 500 seems the minimum my
vertex2 needs to be ready to get probed.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>

board/sunxi/ahci.c

@@ -76,6 +76,8 @@ void scsi_init(void)
 #ifdef CONFIG_SATAPWR
 	gpio_request(CONFIG_SATAPWR, "satapwr");
 	gpio_direction_output(CONFIG_SATAPWR, 1);
+	/* Give attached sata device time to power-up to avoid link timeouts */
+	mdelay(500);
 #endif
 
 	if (sunxi_ahci_phy_init(SUNXI_SATA_BASE) < 0)