Remove newlib workaround from libfdt

libfdt can now use the strnlen implementation from libc.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: Ic97135911d5f6370bdbe49e69c1c70374f15a8f5
diff --git a/external/libfdt/libfdt.cmake b/external/libfdt/libfdt.cmake
index 9da9bba..c3e96f5 100644
--- a/external/libfdt/libfdt.cmake
+++ b/external/libfdt/libfdt.cmake
@@ -1,5 +1,5 @@
 #-------------------------------------------------------------------------------
-# Copyright (c) 2022, Arm Limited and Contributors. All rights reserved.
+# Copyright (c) 2022-2024, Arm Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -18,7 +18,6 @@
 set(GIT_OPTIONS
 	GIT_REPOSITORY ${DTC_URL}
 	GIT_TAG ${DTC_REFSPEC}
-	PATCH_COMMAND git stash COMMAND git apply ${CMAKE_CURRENT_LIST_DIR}/fix-strnlen.patch
 )
 
 include(${TS_ROOT}/tools/cmake/common/LazyFetch.cmake REQUIRED)