Fix USB flightsim on AVR with newer Arduino

usb_flightsim/usb.c

 };
 
 
-static uint8_t PROGMEM rawhid_hid_report_desc[] = {
+static const uint8_t PROGMEM rawhid_hid_report_desc[] = {
         0x06, 0x1C, 0xFF,			// Usage page = 0xFF1C
         0x0A, 0x39, 0xA7,			// Usage = 0xA739
         0xA1, 0x01,                             // Collection 0x01

usb_flightsim/usb_api.cpp

 	uint8_t len, buf[6];
 
 	if (!FlightSim.enabled || !name) return;
-	len = strlen_P((const prog_char*)name);
+	len = strlen_P((const char *)name);
 	buf[0] = len + 6;
 	buf[1] = 1;
 	buf[2] = id;
 	uint8_t len, buf[6];
 
 	if (!FlightSim.enabled || !name) return;
-	len = strlen_P((const prog_char*)name);
+	len = strlen_P((const char *)name);
 	buf[0] = len + 6;
 	buf[1] = 1;
 	buf[2] = id;
 	uint8_t len, buf[6];
 
 	if (!FlightSim.enabled || !name) return;
-	len = strlen_P((const prog_char*)name);
+	len = strlen_P((const char *)name);
 	buf[0] = len + 6;
 	buf[1] = 1;
 	buf[2] = id;
 void FlightSimClass::xmit(const uint8_t *p1, uint8_t n1, const _XpRefStr_ *p2, uint8_t n2)
 {
 	uint8_t intr_state, total, avail;
-	const prog_char *s2 = (const prog_char *)p2;
+	const char *s2 = (const char *)p2;
 
 	total = n1 + n2;
 	if (total > FLIGHTSIM_TX_SIZE) return;