tty: serial: fsl_lpuart: support UPIO_MEM32 for lpuart32

"earlycon" no need to specify the value string since it uses
stdout-path parameters. However when earlycon and normal console
are not using the same uart port, we need specify value string
to earlycon, this is what we need to do when support dual linux
using jailhouse hypervisor. The 2nd linux will use the uart
of the 1st linux as earlycon.

earlycon=lpuart32,mmio32,0x5a060010,115200 not work for i.MX8QXP.
It is because lpuart32_early_console_setup not support little endian.

Since the original code is to support UPIO_MEM32BE, so if not
UPIO_MEM32, we still take it as UPIO_MEM32BE

Acked-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/1576822230-23125-3-git-send-email-peng.fan@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>