input: fix minimum turntable input

DJ Hero does not register input if the turntable is 0, so force it to 1.
This will happen if you map it to the left stick and push it all the way down,
or if you use a keyboard, which sends the max value on key press.

rpcs3/Emu/Io/Turntable.cpp

@@ -264,7 +264,8 @@ void usb_device_turntable::interrupt_transfer(u32 buf_size, u8* buf, u32 /*endpo
 				buf[1] |= 0x01; // Select
 				break;
 			case turntable_btn::right_turntable:
-				buf[6] = 255 - value; // Right Turntable
+				// DJ Hero does not register input if the turntable is 0, so force it to 1.
+				buf[6] = std::max(1, 255 - value); // Right Turntable
 				// DJ Hero requires turntables to be centered at 128.
 				// If this axis ends up centered at 127, force it to 128.
 				if (buf[6] == 127)