rockchip: board: lion-rk3368: increase phy autonegotiation timeout

The first dhcp command consistently fails with a timeout when
the lion-rk3368 board is connected to a Zyxel GS1100-24E
Gigabit Ethernet switch:

  ethernet@ff290000 Waiting for PHY auto negotiation to complete......... TIMEOUT !

Increasing PHY_ANEG_TIMEOUT from the default 4000 to 8000 makes the
first dhcp command work reliably.
Signed-off-by: NJakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com>
Reviewed-by: NPhilipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: NPhilipp Tomsich <philipp.tomsich@theobroma-systems.com>

include/configs/lion_rk3368.h

@@ -12,5 +12,7 @@
 #define KERNEL_LOAD_ADDR		0x280000
 #define DTB_LOAD_ADDR			0x5600000
 #define INITRD_LOAD_ADDR		0x5bf0000
+/* PHY needs longer aneg time at 1G */
+#define PHY_ANEG_TIMEOUT		8000
 
 #endif