serial: lpuart: Enable RX and TX FIFO

Enable the RX and TX FIFO in LPUART driver to avoid the input lost
during U-Boot boot up.

Signed-off-by: Ye Li <ye.li@nxp.com>
Acked-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
1 file changed