serial: imx: factor-out common code to imx_uart_soft_reset()

We perform soft reset in 2 places, slightly differently for no sufficient
reasons, so move more generic variant to a function, and re-use the code.

Out of 2 repeat counters, 10 and 100, select 10, as the code works at
interrupts disabled, and in practice the reset happens immediately.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
Link: https://lore.kernel.org/r/20230201142700.4346-2-sorganov@gmail.com


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