p1: sound: wm8994: fix sound extensions ifdefs

galaxy tab and nexus s have a similar hardware setup
so, this patch uses the same setup and leave generic galaxy tab flag
also, it bring back default sound values and includes

Signed-off-by: Humberto Borba <humberos@gmail.com>
Change-Id: I645af5962f9ea5d6859ef3a38f121aa12a79ce1d