tegra3-common: Start pollyd late

In-call volume problems are related to pollyd not correctly
starting/restarting. It's possible for pollyd to be in a permanent
"stopping" state without an actual running process. Init will not restart
pollyd in this case. This might be a bug in init.

Starting pollyd late seems to make it more reliable.

Change-Id: I38dcab7337da8cc2aa681308202f2124d8cab5aa