Now that the 32bit UP oddity is gone and 32bit uses always a sequence
count, there is no need for the fetch_irq() variants anymore.

Convert to the regular interface.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>