Rockbox

Fast increasing / decreasing of sound settings.

this patch binds ON+UP and ON+DOWN to fastly change
settings in sound options menu.
On the first file, there is a new ( static const int
faststeps[] ) defined in firmware/sound.c, to determine
size of every faststep (volume,balance,bass,stereo
width…)

On the second file, the value of faststep is always set
to 10, that way some very minimal ram is saved, but you
can’t define faststeps size. (say, changing balance
faststep to 15 or 20.)

On Hx00 series, ON+Up/Down used in WPS to change volume
setting by 5.

I don’t own other players so i’ve just ifdefed it a
little not to build for ondio and not to use the WPS
bind for recorers because it’s already been used for
pitch. if this will be exepted there should be some
adjustments.

On WPS by higher steps of 5 instead of 1