tty: serial: samsung: constify s3c24xx_serial_drv_data

The driver data (struct s3c24xx_serial_drv_data) is only used to
initialize the driver properly and is not modified.  Make it const.

Tested-by: Alim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20220308080919.152715-5-krzysztof.kozlowski@canonical.com


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