riscv: sifive: fu540: Setup ethaddr env variable using OTP

This patch extends SiFive FU540 board support to setup ethaddr
env variable based on board serialnum read from OTP.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2 files changed