Convert `TODO` from documentation to a normal comment, and put code in
block.

This was found using the Clippy `doc_markdown` lint, which we may want
to enable.

Fixes: 683a63befc73 ("rust: platform: add basic platform device / driver abstractions")
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/platform.rs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs
index 1297f5292ba9..2426eaf915bb 100644
--- a/rust/kernel/platform.rs
+++ b/rust/kernel/platform.rs
@@ -147,10 +147,11 @@ macro_rules! module_platform_driver {
 ///```
 pub trait Driver {
     /// The type holding driver private data about each device id supported by the driver.
-    ///
-    /// TODO: Use associated_type_defaults once stabilized:
-    ///
-    /// type IdInfo: 'static = ();
+    // TODO: Use associated_type_defaults once stabilized:
+    //
+    // ```
+    // type IdInfo: 'static = ();
+    // ```
     type IdInfo: 'static;

     /// The table of OF device ids supported by the driver.
--
2.49.0