alarmtimer: Hide alarmtimer_suspend event when RTC_CLASS is not configured

alarmtimer: Hide alarmtimer_suspend event when RTC_CLASS is not configured

The trace event alarmtimer_suspend is only called when RTC_CLASS is
defined. As every event created can create up to 5K of text and meta data
regardless if it is called or not it should not be created and waste
memory. Hide the event when CONFIG_RTC_CLASS is not defined.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20250612095828.6d75dfa3@batman.local.home
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>