Assembly support

Update the Arm Clang toolchain file to support assembly files.

Removing cmsis_core dependency. Applications that depend on CMSIS
should add that dependency manually.

Change-Id: I42d68e6734acc88aef8f9af124b5e76079b839b5
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9d20c14..b7d3bea 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2019-2020 Arm Limited. All rights reserved.
+# Copyright (c) 2019-2021 Arm Limited. All rights reserved.
 #
 # SPDX-License-Identifier: Apache-2.0
 #
@@ -67,4 +67,4 @@
 add_subdirectory(drivers)
 
 # Merge libraries into static library
-target_link_libraries(ethosu_core INTERFACE tflu cmsis_core ethosu_applications ethosu_drivers)
+target_link_libraries(ethosu_core INTERFACE tflu ethosu_applications ethosu_drivers)