tests: drivers: dma: Update board config and overlay for adp_xc7k_ae350

1. Add config and overlay file in test scatter_gather for adp_xc7k_ae350
   and adp_xc7k_ae350_clic to support the test case.
2. Modify the config file in test chan_blen_transfer and loop_transfer
   because the tests do not support the NOCACHE memory configuration,
   the DCACHE configuration needs to be disabled.

Signed-off-by: Kevin Wang <kevinwang821020@google.com>