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/AudioResamplerCubic.h b/services/audioflinger/AudioResamplerCubic.h
index 203b933..b315da5 100644
--- a/services/audioflinger/AudioResamplerCubic.h
+++ b/services/audioflinger/AudioResamplerCubic.h
@@ -28,8 +28,8 @@
 
 class AudioResamplerCubic : public AudioResampler {
 public:
-    AudioResamplerCubic(int bitDepth, int inChannelCount, int32_t sampleRate) :
-        AudioResampler(bitDepth, inChannelCount, sampleRate, MED_QUALITY) {
+    AudioResamplerCubic(int inChannelCount, int32_t sampleRate) :
+        AudioResampler(inChannelCount, sampleRate, MED_QUALITY) {
     }
     virtual void resample(int32_t* out, size_t outFrameCount,
             AudioBufferProvider* provider);