lib/libfdt/: General aesthetic/style fixes.

A number of style fixes across the files in this directory, including:

 * Correct invalid kernel-doc content.
 * Tidy up massive comment in fdt_region.c.
 * Use correct spelling of "U-Boot".
 * Replace tests of "! <var>" with "!<var>".
 * Replace "libfdt_env.h" with <libfdt_env.h>.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/libfdt/fdt_rw.c b/lib/libfdt/fdt_rw.c
index 1a358a8..e7321cc 100644
--- a/lib/libfdt/fdt_rw.c
+++ b/lib/libfdt/fdt_rw.c
@@ -3,7 +3,7 @@
  * Copyright (C) 2006 David Gibson, IBM Corporation.
  * SPDX-License-Identifier:	GPL-2.0+ BSD-2-Clause
  */
-#include "libfdt_env.h"
+#include <libfdt_env.h>
 
 #ifndef USE_HOSTCC
 #include <fdt.h>
@@ -168,7 +168,7 @@
 	int err;
 
 	*prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
-	if (! (*prop))
+	if (!(*prop))
 		return oldlen;
 
 	if ((err = _fdt_splice_struct(fdt, (*prop)->data, FDT_TAGALIGN(oldlen),
@@ -283,7 +283,7 @@
 	FDT_RW_CHECK_HEADER(fdt);
 
 	prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
-	if (! prop)
+	if (!prop)
 		return len;
 
 	proplen = sizeof(*prop) + FDT_TAGALIGN(len);