AudioFlinger: fix RecordThread initial device

A regression was introduced when the audio device enums where
modified for a 32 bit representation: the device passed when
constructing a RecordThread was still the concatenation of input
device and output device bit fields on one 32 bit value which
is not possible anymore.

The fix consists in modifying the RecordThread constructor to accept
separate values for input and output devices.

Change-Id: I81fb5f4718428b54251e65d74b86e198ce15193e