dtc: backport patch to export fdt_check_full()

This is required for configure script of QEMU to detect presence of
system libfdt library

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

libs/dtc/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=dtc
 PKG_VERSION:=1.5.0
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_HASH:=c672e443c9f7e39f5a7c8e602da6777f9ad55ad70de87de300a43828c8050172
 PKG_SOURCE_URL:=@KERNEL/software/utils/dtc

libs/dtc/patches/0002-export-fdt_check_full-and-others.patch

@@ -0,0 +1,29 @@
+From eac2ad495b29f15d78daa2a7226653f36515cd7a Mon Sep 17 00:00:00 2001
+From: David Gibson <david@gibson.dropbear.id.au>
+Date: Mon, 25 Mar 2019 14:52:47 +1100
+Subject: [PATCH] Update version.lds again
+
+Yet again, we've added several functions to libfdt that were supposed
+to be exported, but forgotten to add them to the versio.lds script.
+This adds them.
+
+Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
+---
+ libfdt/version.lds | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/libfdt/version.lds b/libfdt/version.lds
+index 9f5d708..a5fe62d 100644
+--- a/libfdt/version.lds
++++ b/libfdt/version.lds
+@@ -66,6 +66,10 @@ LIBFDT_1.2 {
+ 		fdt_resize;
+ 		fdt_overlay_apply;
+ 		fdt_get_string;
++		fdt_get_max_phandle;
++		fdt_check_full;
++		fdt_setprop_placeholder;
++		fdt_property_placeholder;
+ 	local:
+ 		*;
+ };