[build] Mark Xen HVM files as permitted for UEFI Secure Boot

The Xen netfront driver and the core architecture-independent files
such as xenstore.c and xenbus.c are already marked as permitted for
UEFI Secure Boot, but the x86-specific HVM driver (which attaches to
the PCI device and instantiates the Xen devices) is not.

Review the HVM-specific files and mark them as permitted for UEFI
Secure Boot.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/arch/x86/drivers/xen/hvm.c

@@ -22,6 +22,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( PERMITTED );
 
 #include <stdint.h>
 #include <stdio.h>

src/arch/x86/drivers/xen/hvm.h

@@ -8,6 +8,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( PERMITTED );
 
 #include <stdint.h>
 #include <ipxe/xen.h>

src/arch/x86_64/include/ipxe/msr.h

@@ -8,6 +8,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( PERMITTED );
 
 /**
  * Read model-specific register

src/include/ipxe/xenmem.h

@@ -8,6 +8,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( PERMITTED );
 
 #include <ipxe/xen.h>
 #include <xen/memory.h>

src/include/ipxe/xenver.h

@@ -8,6 +8,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( PERMITTED );
 
 #include <ipxe/xen.h>
 #include <xen/version.h>