Merge pull request ARMmbed#1635 from ducky64/nucleo_rpc

Add Nucleo F303K8 pin parsing for RPC

Author: 0xc0170

libraries/rpc/parse_pins.cpp

@@ -59,7 +59,7 @@ PinName parse_pins(const char *str) {
         }
         return port_pin((PortName)port, pin);
 
-#elif defined(TARGET_NUCLEO_F072RB) || defined(TARGET_NUCLEO_F411RE)
+#elif defined(TARGET_NUCLEO_F072RB) || defined(TARGET_NUCLEO_F303K8) || defined(TARGET_NUCLEO_F411RE)
     if (str[0] == 'P') {   // PX_XX e.g.PA_2 PC_15
         uint32_t port = str[1] - 'A';
         uint32_t pin  = str[3] - '0';