fix(platform/timer): add back note of platform timer reference

src/platform/timer.rs

@@ -1,3 +1,6 @@
+// Referenced https://github.com/sheroz/tick_counter (MIT license) as a baseline.
+// Architecturally modified to support UEFI and remove x86 (32-bit) support.
+
 use std::time::Duration;
 
 /// Support for aarch64 timers.