hal: update to add BE channel configuration for USB capture

Update to add BE channel configuration for USB capture and more
BE configuration options for sample rate and channel number.

Change-Id: I1e0af7a19a67aecba5afae95ecc62eec4a2d650b
CRs-Fixed: 1071868
diff --git a/hal/msm8916/platform.h b/hal/msm8916/platform.h
index 1e54ee1..2324111 100644
--- a/hal/msm8916/platform.h
+++ b/hal/msm8916/platform.h
@@ -221,14 +221,14 @@
     HDMI_RX_BACKEND,
     DISP_PORT_RX_BACKEND,
     USB_AUDIO_RX_BACKEND,
+    MAX_RX_CODEC_BACKENDS = USB_AUDIO_RX_BACKEND,
+    /* TX BE follows RX BE */
+    SLIMBUS_0_TX,
+    DEFAULT_CODEC_TX_BACKEND = SLIMBUS_0_TX,
+    USB_AUDIO_TX_BACKEND,
     MAX_CODEC_BACKENDS
 };
-enum {
-    DEFAULT_CODEC_TX_BACKEND,
-    SLIMBUS_0_TX = DEFAULT_CODEC_TX_BACKEND,
-    USB_AUDIO_TX_BACKEND,
-    MAX_CODEC_TX_BACKENDS
-};
+
 #define AUDIO_PARAMETER_KEY_NATIVE_AUDIO "audio.nat.codec.enabled"
 #define AUDIO_PARAMETER_KEY_NATIVE_AUDIO_MODE "native_audio_mode"