x86/boot: tidy #include-s

As of d58a509e01 ("build,x86: remove the need for build32.mk") we
don't need to use non-standard #include forms anymore in the sources for
the boot code helper blobs. The only place where this kind of #include
needs to remain (for the time being) is mkelf32.c.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

xen/arch/x86/boot/defs.h

@@ -20,7 +20,7 @@
 #ifndef __BOOT_DEFS_H__
 #define __BOOT_DEFS_H__
 
-#include "../../../include/xen/stdbool.h"
+#include <xen/stdbool.h>
 
 #define __maybe_unused	__attribute__((__unused__))
 #define __packed	__attribute__((__packed__))

xen/arch/x86/boot/reloc.c

@@ -27,10 +27,11 @@ asm (
     );
 
 #include "defs.h"
-#include "../../../include/xen/multiboot.h"
-#include "../../../include/xen/multiboot2.h"
 
-#include "../../../include/xen/kconfig.h"
+#include <xen/kconfig.h>
+#include <xen/multiboot.h>
+#include <xen/multiboot2.h>
+
 #include <public/arch-x86/hvm/start_info.h>
 
 #ifdef CONFIG_VIDEO