[legal] Add a selection of FILE_LICENCE declarations

Add FILE_LICENCE declarations to almost all files that make up the
various standard builds of gPXE.

src/arch/i386/core/basemem_packet.c

@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 /**
  * @file
  *

src/arch/i386/core/pic8259.c

@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <gpxe/io.h>
 #include <pic8259.h>
 

src/arch/i386/core/rdtsc_timer.c

@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 /** @file
  *
  * RDTSC timer

src/arch/i386/core/relocate.c

@@ -9,6 +9,8 @@
  *
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 /*
  * The linker passes in the symbol _max_align, which is the alignment
  * that we must preserve, in bytes.

src/arch/i386/core/setjmp.S

@@ -1,5 +1,7 @@
 /* setjmp and longjmp. Use of these functions is deprecated. */
 
+FILE_LICENCE ( GPL2_OR_LATER )
+
 	.text
 	.arch i386
 	.code32

src/arch/i386/core/stack.S

@@ -1,3 +1,5 @@
+FILE_LICENCE ( GPL2_OR_LATER )
+
 	.arch i386
 
 /****************************************************************************

src/arch/i386/core/stack16.S

@@ -1,3 +1,5 @@
+FILE_LICENCE ( GPL2_OR_LATER )
+
 	.arch i386
 
 /****************************************************************************

src/arch/i386/core/timer2.c

@@ -11,6 +11,8 @@
  * your option) any later version.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <stddef.h>
 #include <gpxe/timer2.h>
 #include <gpxe/io.h>

src/arch/i386/core/virtaddr.S

@@ -4,6 +4,8 @@
  *
  */
 
+FILE_LICENCE ( GPL2_OR_LATER )
+
 #include "librm.h"
 		
 	.arch i386

src/arch/i386/core/x86_io.c

@@ -16,6 +16,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #include <gpxe/io.h>
 #include <gpxe/x86_io.h>