ARM: dts: aspeed: bletchley: switch spi2 driver to aspeed-smc

Due to DVT schematic has stable spi signal, switch back to aspeed-smc
driver for improving performance.

Signed-off-by: Potin Lai <potin.lai.pt@gmail.com>
Reviewed-by: Patrick Williams <patrick@stwcx.xyz>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20220509151118.4899-3-potin.lai.pt@gmail.com


Signed-off-by: Joel Stanley <joel@jms.id.au>