Commit FS#11364 by me. Increases the A3525v2 volume range by 7.5dB. Each volume...

Commit FS#11364 by me.  Increases the A3525v2 volume range by 7.5dB.  Each volume setting gets 7.5dB louder (if you listened before at 0dB, you would have to set it to about -7.5dB to get the same volume).  As a result, the new 0dB actually is pretty close to max line level for a full scale voltage, so positive dB may clip, whereas before they did not because the scale was off.  Thanks to dfkt and Tim Graf for help figuring this out.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@27101 a1c6a512-1295-4272-9138-f99709370657