rust: rcpufreq_dt: use vertical import style

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

Signed-off-by: Guru Das Srinagesh <linux@gurudas.dev>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/cpufreq/rcpufreq_dt.rs

@@ -4,12 +4,19 @@
 
 use kernel::{
     clk::Clk,
-    cpu, cpufreq,
+    cpu,
+    cpufreq, //
     cpumask::CpumaskVar,
-    device::{Core, Device},
+    device::{
+        Core,
+        Device, //
+    },
     error::code::*,
     macros::vtable,
-    module_platform_driver, of, opp, platform,
+    module_platform_driver,
+    of,
+    opp,
+    platform, //
     prelude::*,
     str::CString,
     sync::Arc,