sci: Add missing param for sci_shutdown prototype.

Author: QuzarDC

kernel/arch/dreamcast/include/dc/sci.h

@@ -146,7 +146,7 @@ void sci_configure_spi(sci_spi_cs_mode_t cs, size_t buffer_size);
 
 /** \brief  Shutdown the SCI port.
 */
-void sci_shutdown();
+void sci_shutdown(void);
 
 /** \brief  Read a single byte from the UART.
     \param  data            Pointer to store the read byte.