spi: s3c64xx: correct kerneldoc of s3c64xx_spi_port_config

Correct the name of s3c64xx_spi_port_config structure in kerneldoc:

  drivers/spi/spi-s3c64xx.c:154: warning:
    expecting prototype for struct s3c64xx_spi_info. Prototype was for struct s3c64xx_spi_port_config instead

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Sylwester Nawrocki <snawrocki@kernel.org>
Link: https://lore.kernel.org/r/20210414203343.203119-2-krzysztof.kozlowski@canonical.com
Signed-off-by: Mark Brown <broonie@kernel.org>