hal: Add support to get active microphones on input stream

Add support to get active microphones on input stream.
Get microphone device id and channel map based on active
usecase and sound device. Active microphone characteristics
are retrieved from platform info using this device id.

Change-Id: I63ec99e70980869097fa896bc4b309fc0583fb3a
diff --git a/hal/msm8974/platform.h b/hal/msm8974/platform.h
index ccbc413..34ab9f6 100644
--- a/hal/msm8974/platform.h
+++ b/hal/msm8974/platform.h
@@ -521,6 +521,9 @@
 #define TX_VOICE_FV5ECNS_DM 0x10F0A
 
 #define LIB_CSD_CLIENT "libcsd-client.so"
+
+#define AUDIO_MAKE_STRING_FROM_ENUM(X)   { #X, X }
+
 /* CSD-CLIENT related functions */
 typedef int (*init_t)(bool);
 typedef int (*deinit_t)();