configs: ax25-ae350: Separate ax25-ae350 for RV32/64I.

Separate ax25-ae350 from one to two for
32 and 64 bit individually. And also select
different dts for 32 and 64 bit.

Signed-off-by: Rick Chen <rick@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>