efi_loader: DocBook comments for boot services

With 'make htmldocs' we can generate a documentation if the function
comments follow the DocBook conventions.

This patch adjusts the comments for EFI boot services and provides the
DocBook template for the EFI subsystem.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/doc/DocBook/Makefile b/doc/DocBook/Makefile
index 820b1fb..5257613 100644
--- a/doc/DocBook/Makefile
+++ b/doc/DocBook/Makefile
@@ -7,7 +7,7 @@
 # To add a new book the only step required is to add the book to the
 # list of DOCBOOKS.
 
-DOCBOOKS := linker_lists.xml stdio.xml
+DOCBOOKS := efi.xml linker_lists.xml stdio.xml
 
 ###
 # The build process is as follows (targets):