drm/nova: use vertical import style

Convert `use` imports to vertical layout for better readability and
maintainability.

Signed-off-by: Guru Das Srinagesh <linux@gurudas.dev>

Author: Guru Das Srinagesh

drivers/gpu/drm/nova/file.rs

@@ -4,7 +4,10 @@ use crate::driver::{NovaDevice, NovaDriver};
 use crate::gem::NovaObject;
 use kernel::{
     alloc::flags::*,
-    drm::{self, gem::BaseObject},
+    drm::{
+        self,
+        gem::BaseObject, //
+    },
     pci,
     prelude::*,
     uapi,

drivers/gpu/drm/nova/gem.rs

@@ -2,7 +2,11 @@
 
 use kernel::{
     drm,
-    drm::{gem, gem::BaseObject, DeviceContext},
+    drm::{
+        gem,
+        gem::BaseObject,
+        DeviceContext, //
+    },
     page,
     prelude::*,
     sync::aref::ARef,