tty: serial: fsl_lpuart: add LS1028A earlycon support

Add a early_console_setup() for the LS1028A SoC with 32bit, little
endian access. If the bootloader does a fixup of the clock-frequency
node the baudrate divisor register will automatically be set.

Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200306214433.23215-5-michael@walle.cc


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>