uboot-sunxi: randomize ethaddr on Olimex A20 boards

While these boards have an at24 EEPROM for storing the MAC address,
early revisions (up until about 2017) did not contain actual addresses.
Create a random address to have ethernet function properly in u-boot.

Signed-off-by: Zoltan HERPAI <[email protected]>

package/boot/uboot-sunxi/patches/260-sunxi-a20-random-ethaddr-on-olinuxino-micro.patch

@@ -0,0 +1,7 @@
+--- a/configs/A20-OLinuXino_MICRO_defconfig
++++ b/configs/A20-OLinuXino_MICRO_defconfig
+@@ -26,3 +26,4 @@ CONFIG_AXP_ALDO4_VOLT=2800
+ CONFIG_SCSI=y
+ CONFIG_USB_EHCI_HCD=y
+ CONFIG_USB_OHCI_HCD=y
++CONFIG_NET_RANDOM_ETHADDR=y