entry: Move irqentry_enter() prototype later

entry: Move irqentry_enter() prototype later

Subsequent patches will rework the irqentry_*() functions. The end
result (and the intermediate diffs) will be much clearer if the
prototype for the irqentry_enter() function is moved later, immediately
before the prototype of the irqentry_exit() function.

Move the prototype later.

This is purely a move; there should be no functional change as a result
of this change.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260407131650.3813777-4-mark.rutland@arm.com