Add BOARD_KERNEL_BINARIES to board_config.mk

Test: pass
Change-Id: Ic670a1c60d6ab2beca593da5941f56d4f3b76c3c
diff --git a/core/board_config.mk b/core/board_config.mk
index d4fe618..43a34f9 100644
--- a/core/board_config.mk
+++ b/core/board_config.mk
@@ -91,6 +91,10 @@
 
 _board_strip_readonly_list += $(_dynamic_partitions_var_list)
 
+# Kernel related variables
+_board_strip_readonly_list += \
+  BOARD_KERNEL_BINARIES \
+
 _build_broken_var_list := \
   BUILD_BROKEN_DUP_RULES \
   BUILD_BROKEN_ELF_PREBUILT_PRODUCT_COPY_FILES \