libfdt: move headers to <linux/libfdt.h> and <linux/libfdt_env.h>

Thomas reported U-Boot failed to build host tools if libfdt-devel
package is installed because tools include libfdt headers from
/usr/include/ instead of using internal ones.

This commit moves the header code:
  include/libfdt.h         -> include/linux/libfdt.h
  include/libfdt_env.h     -> include/linux/libfdt_env.h

and replaces include directives:
  #include <libfdt.h>      -> #include <linux/libfdt.h>
  #include <libfdt_env.h>  -> #include <linux/libfdt_env.h>

Reported-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/core/of_access.c b/drivers/core/of_access.c
index c31cba7..9389199 100644
--- a/drivers/core/of_access.c
+++ b/drivers/core/of_access.c
@@ -21,7 +21,7 @@
  */
 
 #include <common.h>
-#include <libfdt.h>
+#include <linux/libfdt.h>
 #include <dm/of_access.h>
 #include <linux/ctype.h>
 #include <linux/err.h>
diff --git a/drivers/core/of_addr.c b/drivers/core/of_addr.c
index 4757066..7513ea2 100644
--- a/drivers/core/of_addr.c
+++ b/drivers/core/of_addr.c
@@ -8,7 +8,7 @@
  */
 
 #include <common.h>
-#include <libfdt.h>
+#include <linux/libfdt.h>
 #include <dm/of_access.h>
 #include <dm/of_addr.h>
 #include <linux/err.h>
diff --git a/drivers/core/of_extra.c b/drivers/core/of_extra.c
index 0381909..ca2e92b 100644
--- a/drivers/core/of_extra.c
+++ b/drivers/core/of_extra.c
@@ -6,7 +6,7 @@
  */
 
 #include <common.h>
-#include <libfdt.h>
+#include <linux/libfdt.h>
 #include <dm/of_access.h>
 #include <dm/of_extra.h>
 #include <dm/ofnode.h>
diff --git a/drivers/core/ofnode.c b/drivers/core/ofnode.c
index d0bdea0..4e45326 100644
--- a/drivers/core/ofnode.c
+++ b/drivers/core/ofnode.c
@@ -9,7 +9,7 @@
 #include <dm.h>
 #include <fdtdec.h>
 #include <fdt_support.h>
-#include <libfdt.h>
+#include <linux/libfdt.h>
 #include <dm/of_access.h>
 #include <dm/of_addr.h>
 #include <dm/ofnode.h>
diff --git a/drivers/core/regmap.c b/drivers/core/regmap.c
index 0f1d308..8a0e00f 100644
--- a/drivers/core/regmap.c
+++ b/drivers/core/regmap.c
@@ -8,7 +8,7 @@
 #include <common.h>
 #include <dm.h>
 #include <errno.h>
-#include <libfdt.h>
+#include <linux/libfdt.h>
 #include <malloc.h>
 #include <mapmem.h>
 #include <regmap.h>
diff --git a/drivers/core/root.c b/drivers/core/root.c
index 36336b6..3a426ab 100644
--- a/drivers/core/root.c
+++ b/drivers/core/root.c
@@ -11,7 +11,7 @@
 #include <errno.h>
 #include <fdtdec.h>
 #include <malloc.h>
-#include <libfdt.h>
+#include <linux/libfdt.h>
 #include <dm/device.h>
 #include <dm/device-internal.h>
 #include <dm/lists.h>
diff --git a/drivers/core/util.c b/drivers/core/util.c
index aaaed4e..24abe14 100644
--- a/drivers/core/util.c
+++ b/drivers/core/util.c
@@ -6,7 +6,7 @@
 
 #include <common.h>
 #include <dm/util.h>
-#include <libfdt.h>
+#include <linux/libfdt.h>
 #include <vsprintf.h>
 
 #ifdef CONFIG_DM_WARN