target/cortex_a: Use bool data type

Change-Id: Ieea3dc05809263aa0eba5125d52fef3fe77e9c5a
Signed-off-by: Marc Schink <dev@zapb.de>
Reviewed-on: http://openocd.zylin.com/6289
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

src/target/cortex_a.h

@@ -64,7 +64,7 @@ enum cortex_a_dacrfixup_mode {
 };
 
 struct cortex_a_brp {
-	int used;
+	bool used;
 	int type;
 	uint32_t value;
 	uint32_t control;
@@ -72,7 +72,7 @@ struct cortex_a_brp {
 };
 
 struct cortex_a_wrp {
-	int used;
+	bool used;
 	uint32_t value;
 	uint32_t control;
 	uint8_t WRPn;