hal: changes to support 24 bit record

-Changes to support 24 bit record if input format request is
 AUDIO_FORMAT_PCM_8_24_BIT or AUDIO_FORMAT_PCM_24_BIT_PACKED

Change-Id: I68076524ccccbf9f0be3c88bb01180ae7e4fd8b1
diff --git a/hal/audio_hw.h b/hal/audio_hw.h
index a1d69a6..31184d5 100644
--- a/hal/audio_hw.h
+++ b/hal/audio_hw.h
@@ -247,7 +247,8 @@
     audio_input_flags_t flags;
     bool is_st_session;
     bool is_st_session_active;
-
+    int sample_rate;
+    int bit_width;
     struct audio_device *dev;
 };