fix(lz4): do not expose internal lz4.h (#5069)

Signed-off-by: Xu Xingliang <xuxingliang@xiaomi.com>

lvgl.h

@@ -107,7 +107,6 @@ extern "C" {
 #include "src/libs/rlottie/lv_rlottie.h"
 #include "src/libs/ffmpeg/lv_ffmpeg.h"
 #include "src/libs/tiny_ttf/lv_tiny_ttf.h"
-#include "src/libs/lz4/lz4.h"
 
 #include "src/layouts/lv_layout.h"
 

src/libs/bin_decoder/lv_bin_decoder.c

@@ -12,7 +12,14 @@
 #include "../../stdlib/lv_string.h"
 #include "../../stdlib/lv_sprintf.h"
 #include "../../libs/rle/lv_rle.h"
-#include "../../libs/lz4/lz4.h"
+
+#if LV_USE_LZ4_EXTERNAL
+    #include <lz4.h>
+#endif
+
+#if LV_USE_LZ4_INTERNAL
+    #include "../../libs/lz4/lz4.h"
+#endif
 
 /*********************
  *      DEFINES