refactor(mpam): remove unused function declaration

Change-Id: Ia660b6554fe4544effd1810e1aca202f95e3c447
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
diff --git a/include/lib/extensions/mpam.h b/include/lib/extensions/mpam.h
index ac8c00a..414adcb 100644
--- a/include/lib/extensions/mpam.h
+++ b/include/lib/extensions/mpam.h
@@ -9,7 +9,6 @@
 
 #include <stdbool.h>
 
-bool mpam_supported(void);
 void mpam_enable(bool el2_unused);
 
 #endif /* MPAM_H */