Fix gamepad emulated mouse inputs not showing in mapper sometimes

[rsn8887]

Before this fix, the gamepad emulated mouse input mappings:

Emulated Mouse X Axis
Emulated Mouse Y Axis
Emulated Mouse Left Click
Emulated Mouse Right Click
Emulated Mouse Slow Down
Emulated Mouse Speed Up

did not appear in the mapper if player one input device was set to joystick or gamepad AND player two input type was also set to joystick or gamepad.

With this fix, the gamepad emulated mouse input mappings always appear in the mapper as long as player one input device is either set to joystick or gamepad, regardless of what is set for player two.

The mouse mapping choices only appear if the core option Input: Enable gamepad emulated mouse is set to true, just as before.

These mappings are really important, because they allow control of mouse-based dos games with only a gamepad. The default mappings are as they were:

right analog stick for mouse motion
L2/R2 for mouse buttons
L/R for slow/fast mouse speed modifiers

but they can be re-mapped in the mapper.

These inputs always worked, just the remapping was not available sometimes.

[rsn8887]

I tested this on Switch and it works.

[realnc]

Thanks!