Switch to using llvm-strip for modules

The gcc tools are deprecated; replace with the llvm equivalent.

Bug: 158484106
Change-Id: I9c3717bde281667eec82cc21dc63dc7fd5592a46
diff --git a/core/Makefile b/core/Makefile
index eafcf9b..27e41fe 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -206,7 +206,7 @@
 
 define copy-and-strip-kernel-module
 $(2): $(1)
-	$($(LOCAL_2ND_ARCH_VAR_PREFIX)TARGET_STRIP) -o $(2) --strip-debug $(1)
+	$(LLVM_STRIP) -o $(2) --strip-debug $(1)
 endef
 
 # $(1): modules list