fpga: Use Castor specific VID/PID in UDI

Allows an app to determine which type of device it is running on.

- Reserve vendor ID 0x7357 for people using Unlocked.
- Use Castor product ID.
- Serial number is just nonsense, as before.

hw/application_fpga/data/udi.hex

@@ -1,2 +1,2 @@
-00010203
+073570c0
 04050607

hw/application_fpga/fw/testapp/main.c

@@ -122,8 +122,8 @@ int main(void)
 	// But a syscall to get parts of UDI should be able to run
 	int vidpid = syscall(TK1_SYSCALL_GET_VIDPID, 0, 0, 0);
 
-	if (vidpid != 0x00010203) {
-		failmsg("Expected VID/PID to be 0x00010203");
+	if (vidpid != 0x073570c0) {
+		failmsg("Expected VID/PID to be 0x073570c0");
 		anyfailed = 1;
 	}