Replace int bitDepth with audio_format_t in Resampler

Remove mBitDepth from class (not used).
Replace with audio_format_t in factory method to distinguish
between float and pcm 16-bit.

Change-Id: I166860796c68285077ef4458d8758d19b82523f9
diff --git a/services/audioflinger/AudioResamplerSinc.h b/services/audioflinger/AudioResamplerSinc.h
index 1ea4474..97ae3d0 100644
--- a/services/audioflinger/AudioResamplerSinc.h
+++ b/services/audioflinger/AudioResamplerSinc.h
@@ -34,7 +34,7 @@
 
 class AudioResamplerSinc : public AudioResampler {
 public:
-    AudioResamplerSinc(int bitDepth, int inChannelCount, int32_t sampleRate,
+    AudioResamplerSinc(int inChannelCount, int32_t sampleRate,
             src_quality quality = HIGH_QUALITY);
 
     virtual ~AudioResamplerSinc();