Do some cleanup for lpuart driver, no functionality change.

Changes in V3:
1. Add the change to covert unsigned char to u8 in the first patch as Jiri suggested.

Changes in V2:
1. Add the third patch to rename the register variables as Jiri suggested.

Sherry Sun (3):
  tty: serial: fsl_lpuart: Use u32 and u8 for register variables
  tty: serial: fsl_lpuart: use port struct directly to simply code
  tty: serial: fsl_lpuart: rename register variables more specifically

 drivers/tty/serial/fsl_lpuart.c | 469 ++++++++++++++++----------------
 1 file changed, 231 insertions(+), 238 deletions(-)

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2.34.1