I'm not saying it isn't possible, but joystick support in android is still pretty sketchy. Most of the joysticks you see for android are actually keyboards and/or they have a driver to make them show up as a keyboard. Understand that most of those are connected via Bluetooth. The usb connector is fairly useless for most gamepads and joysticks due to lack of true joystick support in android. I mean some HID joysticks show up fine and the 360 gamepad works on a lot of tablets, but a wheel is decidedly a non-standard device.
Common sense would say it doesn't matter regardless. Most of the racing games in mame require at least a middle of the road pc to emulate. A tablet won't be powerful enough unless you are playing sprint 8 or something. Even if it was, most people spend 200+ on a wheel so they aren't going to skimp on the pc.