efi: Add a comment about duplicated ELF constants

These constants are defined in arch-specific code but redefined here. Add
a TODO to clean this up.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

lib/efi_loader/efi_runtime.c

@@ -28,6 +28,10 @@ static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void);
 static efi_status_t __efi_runtime EFIAPI efi_device_error(void);
 static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void);
 
+/*
+ * TODO(sjg@chromium.org): These defines and structs should come from the elf
+ * header for each arch (or a generic header) rather than being repeated here.
+ */
 #if defined(CONFIG_ARM64)
 #define R_RELATIVE	1027
 #define R_MASK		0xffffffffULL