riscv: ae350: Use fdtdec_get_addr_size_auto_noparent to parse smc reg

Use fdtdec_get_addr_size_auto_noparent to read the "reg" property
instead of fdtdec_get_addr. This will increase the compatibility
of dtb parsing.

Signed-off-by: Rick Chen <rick@andestech.com>
Acked-by: Leo Liang <ycliang@andestech.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Leo Liang <ycliang@andestech.com>