staging: bcm2835-audio: Remove code for non device tree init

The bcm2835-audio driver has a legacy code path for initializing
devices without a device tree.  Delete this code path and remove
the non device tree devices.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>