diag: Synchronize threads to fix possible deadlock

This patch fixes the possible deadlock during processing
of feature mask between different peripherals.

CRs-Fixed: 1101672
Change-Id: I4d4223275c03017ef367bafa8e55be1803b9a750
Signed-off-by: Manoj Prabhu B <bmanoj@codeaurora.org>
diff --git a/drivers/char/diag/diagchar.h b/drivers/char/diag/diagchar.h
index 73e0e88..d3dde50 100644
--- a/drivers/char/diag/diagchar.h
+++ b/drivers/char/diag/diagchar.h
@@ -548,7 +548,7 @@
 	struct mutex diag_id_mutex;
 	struct mutex cmd_reg_mutex;
 	uint32_t cmd_reg_count;
-	struct mutex diagfwd_channel_mutex;
+	struct mutex diagfwd_channel_mutex[NUM_PERIPHERALS];
 	/* Sizes that reflect memory pool sizes */
 	unsigned int poolsize;
 	unsigned int poolsize_hdlc;