nds32: dts: Fix mmc node compatible string

In the two commits:
cf3922dd
mmc: ftsdc010_mci: Sync compatible with DT mmc node

c14e90e8
riscv: dts: Sync DT with Linux Kernel

ftsdc010_mci's compatible has been modified as
"andestech,atfsdc010" for RISC-V synchronization.
But ae3xx.dts and ag101p.dts which are used for
nds32 adp-ae3xx and adp-ag101p platforms did not
be modified correctly at that time. It will cause
mmc detection failure. Fix it here.

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