[PATCH v6] tty: serial: add Freescale lpuart driver support

[Lu Jingchang-B35083]

>This breaks the build on x86 systems with:
>  CC [M]  drivers/tty/serial/fsl_lpuart.o
>drivers/tty/serial/fsl_lpuart.c: In function ‘lpuart_probe’:
>drivers/tty/serial/fsl_lpuart.c:751:2: error: implicit declaration of
>function ‘of_alias_get_id’ [-Werror=implicit-function-declaration]
>
[Lu Jingchang-B35083] 
I will send the v7 patch with this error fixed. Thanks!