mx6cuboxi: Fix the reset delay for the AR8035 PHY

Since commit 59370f3fcd ("net: phy: delay only if reset handler is
registered") Ethernet is no longer functional:

Booting from net ...
FEC Waiting for PHY auto negotiation to complete......... TIMEOUT !
BOOTP broadcast 1
BOOTP broadcast 2
BOOTP broadcast 3
BOOTP broadcast 4

This commit does not have an issue in itself, but it revelead a problem
with the Ethernet initialization.

As per the AR8035 datasheet:

"For a reliable power on reset, suggest to keep asserting the reset
low long enough (10ms) to ensure the clock is stable and clock-to-reset
1ms requirement is satisfied."

So do as suggested and keep the reset low for 10ms.

Also add a 100us delay after deasserting the reset line
to guarantee that the PHY ID can be read correctly and the Atheros
PHY can be loaded as per Troy Kisky's suggestion.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Tested-by: Tom Rini <trini@konsulko.com>

board/solidrun/mx6cuboxi/mx6cuboxi.c

@@ -143,8 +143,9 @@ static void setup_iomux_enet(void)
 	SETUP_IOMUX_PADS(enet_pads);
 
 	gpio_direction_output(ETH_PHY_RESET, 0);
-	mdelay(2);
+	mdelay(10);
 	gpio_set_value(ETH_PHY_RESET, 1);
+	udelay(100);
 }
 
 int board_phy_config(struct phy_device *phydev)