libc: Remove sscanf() and timingsafe_bcmp()

sscanf() is unused and it doesn't work, so it doesn't make sense to
keep it.

timingsafe_bcmp() isn't used anywhere.

Change-Id: Ib5d28ff21d0f3ccc36c5c0fb5474b3384105cf80
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/lib/libc/libc.mk b/lib/libc/libc.mk
index ded3d74..022e6bf 100644
--- a/lib/libc/libc.mk
+++ b/lib/libc/libc.mk
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -12,14 +12,12 @@
 			printf.c			\
 			putchar.c			\
 			puts.c				\
-			sscanf.c			\
 			strchr.c			\
 			strcmp.c			\
 			strlen.c			\
 			strncmp.c			\
 			strnlen.c			\
-			subr_prf.c			\
-			timingsafe_bcmp.c)
+			subr_prf.c)
 
 INCLUDES	+=	-Iinclude/lib/libc		\
 			-Iinclude/lib/libc/sys