Uncalibrated accelerometer data from the Nunchuck

[mardy]

Bug Report

This was found while adding sensor information to the SDL2 port.

What's the issue you encountered?

Values of the gforce field of the nunchuck_t structure are wrongly scaled: instead of having 1.0 as the base gravity value (like the gforce field of the wiimote), it looks like their base value is about 0.3.

How can the issue be reproduced?

Run the test/testgamecontroller.elf program from the SDL2 tree.

Environment?

Dolphin emulator with a real WiiMote connected, and a Wii as well.