Fix MISRA defects in BL31 common code

Change-Id: I5993b425445ee794e6d2a792c244c0af53640655
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/include/bl31/ehf.h b/include/bl31/ehf.h
index c60b04c..f35d810 100644
--- a/include/bl31/ehf.h
+++ b/include/bl31/ehf.h
@@ -14,7 +14,7 @@
 #include <utils_def.h>
 
 /* Valid priorities set bit 0 of the priority handler. */
-#define EHF_PRI_VALID_	(((uintptr_t) 1) << 0)
+#define EHF_PRI_VALID_	BIT(0)
 
 /* Marker for no handler registered for a valid priority */
 #define EHF_NO_HANDLER_	(0U | EHF_PRI_VALID_)