iPod Classic: minor modifications in TIMER

The current behaviour should not change.

Change-Id: Ia8f44cdccf41dbc3881722f9aebab91de51a9bc5
iPod Classic: configure piezo GPIO ports

Configures piezo GPIO ports for the lowest power consumption
when not in use.

Change-Id: If80b0c947f197277972fd9319b8ab283cca96d3c