Add troubleshooting for slow mouse updates

[asb]

A small number of users might experience a slow/laggy mouse with more recent kernel updates (mostly wireless mice have the issue). See raspberrypi/linux#642 for a full discussion of the problem. The fix is to add usbhid.mousepoll=0 to /boot/cmdline.txt, though I expect to add an option to do this for you to raspi-config's advanced option section shortly.

[jkcoaster]

Thanks! that worked to speed up my mouse as it was acting strange, moving slowly

[ebenupton]

@asb - did you add this option? @popcornmix - should we remove this for ARMv7

[JamesH65]

@popcornmix @pelwell I remember this from ages ago (think I came up with the mousepoll thing!) and apparently this is still there according to the linked issue. Should we add this to the documentation?

[pelwell]

Of course - make it so.

[JamesH65]

I've submitted a PR to add a page describing the kernel command line, #523, which covers this. Once that PR is accepted I will close this.

[JamesH65]

#523 now merged.