efi/libstub: Introduce symbolic constants for the stub major/minor version

Now that we have added new ways to load the initrd or the mixed mode
kernel, we will also need a way to tell the loader about this. Add
symbolic constants for the PE/COFF major/minor version numbers (which
fortunately have always been 0x0 for all architectures), so that we
can bump them later to document the capabilities of the stub.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

include/linux/pe.h

@@ -10,6 +10,9 @@
 
 #include <linux/types.h>
 
+#define LINUX_EFISTUB_MAJOR_VERSION		0x0
+#define LINUX_EFISTUB_MINOR_VERSION		0x0
+
 #define MZ_MAGIC	0x5a4d	/* "MZ" */
 
 #define PE_MAGIC		0x00004550	/* "PE\0\0" */