tty: serial: samsung_tty: set dma burst_size to 1

tty: serial: samsung_tty: set dma burst_size to 1

The src_maxburst and dst_maxburst have been changed to 1 but the settings
of the UCON register aren't changed yet. They should be changed as well
according to the dmaengine slave config.

Fixes: aa2f80e752c7 ("serial: samsung: fix maxburst parameter for DMA transactions")
Cc: stable <stable@kernel.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Link: https://lore.kernel.org/r/20220627065113.139520-1-chanho61.park@samsung.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>