hal: define default HOSTLESS macros to invalid id

Fixing compilation error for targets not using
HOSTLESS architecture.

Change-Id: Idbc8ad4ecd2d767ab5ffb880c780f0f46aa08936
diff --git a/hal/msm8974/platform.h b/hal/msm8974/platform.h
index 1a56ece..07e26af 100644
--- a/hal/msm8974/platform.h
+++ b/hal/msm8974/platform.h
@@ -616,6 +616,13 @@
 #define VOWLAN_CALL_PCM_DEVICE 36
 #endif
 
+#ifndef HOST_LESS_RX_ID
+#define HOST_LESS_RX_ID -1
+#endif
+#ifndef HOST_LESS_TX_ID
+#define HOST_LESS_TX_ID -1
+#endif
+
 #ifdef PLATFORM_MSM8996
 #define VOICEMMODE1_CALL_PCM_DEVICE 2
 #define VOICEMMODE2_CALL_PCM_DEVICE 22