sunxi: board: Move USB ethernet initialization to board_late_init()

For the sake of consistency (*) and order of initialization, i.e.
after we have got the ethernet address, interrupt and timer initialized,
try to initialize USB ethernet gadget.

*) for example, zynqmp uses same order.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index fbe9087..54762ce 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1045,6 +1045,7 @@
 	select SPL_USE_TINY_PRINTF
 	select USE_PREBOOT
 	select SYS_RELOC_GD_ENV_ADDR
+	imply BOARD_LATE_INIT
 	imply CMD_DM
 	imply CMD_GPT
 	imply CMD_UBI if MTD_RAW_NAND