mx6cuboxi: migrate to DM_SERIAL

Add the needed DT overrides to enable UART in SPL.

Cc: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Tested-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Fabio Estevam <festevam@denx.de>
3 files changed