add serial 8 description for sl-can port

Co-authored-by: Henry Wurzburg <[email protected]>

libraries/AP_HAL_ChibiOS/hwdef/SkySakuraH743/README.md

@@ -36,7 +36,7 @@ receive pin for UARTn. The Tn pin is the transmit pin for UARTn.
 |SERIAL5|TX4/RX4|UART4 (RCIN, DMA-enabled)|
 |SERIAL6|TX6/RX6|UART6 (VTX, DMA-enabled)|
 |SERIAL7|TX8/RX8|UART8 (ESC-Telemetry)|
-
+|SERIAL8|COMPUTER|USB|
 ## Safety Button
 SkySakura H743 supports safety button, with connection to sh1.0 6 pin connector, with buzzer and safety led on the same connector.
 Safety button is default to be disabled and can be enabled by setting the following parameter: