doc: documentation of EFI driver binding protocol

* Convert code comments in include/efi_driver.h to Sphinx style.
* Add include/efi_driver.h to the HTML documentation.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/doc/api/efi.rst b/doc/api/efi.rst
index 2b96783..43d6f93 100644
--- a/doc/api/efi.rst
+++ b/doc/api/efi.rst
@@ -172,6 +172,12 @@
 .. kernel-doc:: lib/efi_loader/efi_firmware.c
    :internal:
 
+Driver binding protocol
+~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: include/efi_driver.h
+   :internal:
+
 Unit testing
 ------------