Add install target & GCC support

Add install target for libraries.

Minor changes to enable GCC support.

Change-Id: I6adab92cb997c1edc2729f02a4f10406463e0a9b
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 22a039b..a59231f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -55,4 +55,4 @@
 include(tensorflow.cmake)
 
 # Merge libraries into static library
-target_link_libraries(ethosu_core INTERFACE tflu cmsis_device)
+target_link_libraries(ethosu_core INTERFACE tflu cmsis_core cmsis_device)