msm: bam_dmux: send ack to A2 for 9615 fallback

A2 requires a wakeup ack in the bam to bam fallback case, otherwise A2
might stall waiting for it or assert.

Change-Id: I8ae1e7d8f1ba85ad4834ff09c0b10dd88a50669e
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
diff --git a/arch/arm/mach-msm/bam_dmux.c b/arch/arm/mach-msm/bam_dmux.c
index 4dac062..89d7fc9 100644
--- a/arch/arm/mach-msm/bam_dmux.c
+++ b/arch/arm/mach-msm/bam_dmux.c
@@ -2036,6 +2036,7 @@
 		goto register_bam_failed;
 	}
 	a2_device_handle = h;
+	toggle_apps_ack();
 
 	return 0;