doc: add include/dm/platdata.h to the HTML documentation

Correct Sphinx style comments in include/dm/platdata.h
and add the associated API to the HTML documentation.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/include/dm/platdata.h b/include/dm/platdata.h
index 4efb1df..47ba8aa 100644
--- a/include/dm/platdata.h
+++ b/include/dm/platdata.h
@@ -40,7 +40,7 @@
 #endif
 
 /**
- * driver_rt - runtime information set up by U-Boot
+ * struct driver_rt - runtime information set up by U-Boot
  *
  * There is one of these for every driver_info in the linker list, indexed by
  * the driver_info idx value.
@@ -51,7 +51,7 @@
 	struct udevice *dev;
 };
 
-/**
+/*
  * NOTE: Avoid using these except in extreme circumstances, where device tree
  * is not feasible (e.g. serial driver in SPL where <8KB of SRAM is
  * available). U-Boot's driver model uses device tree for configuration.