ntp: Clean up comments

ntp: Clean up comments

Usage of different comment formatting makes fast reading and parsing the
code harder. There are several multi-line comments which do not follow the
coding style by starting with a line only containing '/*'. There are also
comments which do not start with capitals.

Clean up all those comments to be consistent and remove comments which
document the obvious.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/all/20240911-devel-anna-maria-b4-timers-ptp-ntp-v1-3-2d52f4e13476@linutronix.de