doc: pytest: Document the test_efi_loader test

Add this test to the documentation. We need to add a code-block
annotation to the example and indent it correctly. We also need to
document the do_test_efi_helloworld_net function and that in turn means
changing the documentation to test_efi_helloworld_net_http and
test_efi_helloworld_net_tftp to reflect what is and isn't done in those
functions themselves now.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/doc/develop/pytest/test_efi_loader.rst b/doc/develop/pytest/test_efi_loader.rst
new file mode 100644
index 0000000..da2fa7e
--- /dev/null
+++ b/doc/develop/pytest/test_efi_loader.rst
@@ -0,0 +1,8 @@
+test_efi_loader
+===============
+
+.. automodule:: test_efi_loader
+   :synopsis:
+   :member-order: bysource
+   :members:
+   :undoc-members: