efi: Update some comments related to smbios tables

Clarify the operation of this code with some additional comments.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 0c286bf..c66252a 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -214,6 +214,13 @@
 /* Called by bootefi to make the watchdog available */
 efi_status_t efi_watchdog_register(void);
 /* Called by bootefi to make SMBIOS tables available */
+/**
+ * efi_smbios_register() - write out SMBIOS tables
+ *
+ * Called by bootefi to make SMBIOS tables available
+ *
+ * @return 0 if OK, -ENOMEM if no memory is available for the tables
+ */
 efi_status_t efi_smbios_register(void);
 
 struct efi_simple_file_system_protocol *
diff --git a/include/smbios.h b/include/smbios.h
index 79880ef..97b9ddc 100644
--- a/include/smbios.h
+++ b/include/smbios.h
@@ -231,8 +231,9 @@
  *
  * This writes SMBIOS table at a given address.
  *
- * @addr:	start address to write SMBIOS table
- * @return:	end address of SMBIOS table
+ * @addr:	start address to write SMBIOS table. If this is not
+ *	16-byte-aligned then it will be aligned before the table is written
+ * @return:	end address of SMBIOS table (and start address for next entry)
  */
 ulong write_smbios_table(ulong addr);