build: Refactor the stack trace lib. [1/1]

PD#SWPL-68240

Problem:
Refactor for all.

Solution:
Refactor the stack trace lib.

Verify:
N/A

Change-Id: Iaa08360b3129a7bdfdc7fab36ef295a8f3b10f2e
Signed-off-by: Xiaohu.Huang <xiaohu.huang@amlogic.com>
diff --git a/symtable.mk b/symtable.mk
index f0f307a..286541f 100644
--- a/symtable.mk
+++ b/symtable.mk
@@ -23,4 +23,9 @@
 
 .PHONY: backtrace
 backtrace:
-	@$(call cmd,smap)
\ No newline at end of file
+	@$(call cmd,smap)
+
+.PHONY: clean
+clean:
+	@truncate -s 0 $(B_PRJDIR)/libs/stack_trace/system_map_addr.c
+	@truncate -s 0 $(B_PRJDIR)/libs/stack_trace/system_map_sym.c