audio-driver: Update build files for sa6155

Enable conditional build for audio driver modules
specific to sa6155.

Change-Id: I58701a907242afcfe230623ff42b47c001e3d5f4
Signed-off-by: Rahul Sharma <rahsha@codeaurora.org>

asoc/machine_615x_init.c

@@ -19,14 +19,12 @@
 static int __init audio_machine_615x_init(void)
 {
 	sm6150_init();
-	sa6155_init();
 	return 0;
 }
 
 static void audio_machine_615x_exit(void)
 {
 	sm6150_exit();
-	sa6155_exit();
 }
 
 module_init(audio_machine_615x_init);