Fix MISRA defects in extension libs

No functional changes.

Change-Id: I2f28f20944f552447ac4e9e755493cd7c0ea1192
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/include/lib/extensions/sve.h b/include/lib/extensions/sve.h
index 9c7f37f..83df177 100644
--- a/include/lib/extensions/sve.h
+++ b/include/lib/extensions/sve.h
@@ -4,10 +4,12 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#ifndef __SVE_H__
-#define __SVE_H__
+#ifndef SVE_H
+#define SVE_H
 
-int sve_supported(void);
-void sve_enable(int el2_unused);
+#include <stdbool.h>
+
+bool sve_supported(void);
+void sve_enable(bool el2_unused);
 
-#endif /* __SVE_H__ */
+#endif /* SVE_H */