arm_jtag_t -> struct arm_jtag

Remove misleading typedef and redundant suffix from struct arm_jtag.

src/target/cortex_m3.h

@@ -139,7 +139,7 @@ typedef struct  cortex_m3_dwt_comparator_s
 typedef struct cortex_m3_common_s
 {
 	int common_magic;
-	arm_jtag_t jtag_info;
+	struct arm_jtag jtag_info;
 
 	/* Context information */
 	uint32_t dcb_dhcsr;