ARM: dts: aspeed: wedge40: Remove redundant ADC device

Remove ADC device from wedge40 device tree because the device is already
enabled in "ast2400-facebook-netbmc-common.dtsi".

Signed-off-by: Tao Ren <rentao.bupt@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20210719001724.6410-3-rentao.bupt@gmail.com


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