pinctrl: renesas: rzt2h: Fix invalid wait context

pinctrl: renesas: rzt2h: Fix invalid wait context

The rzt2h_gpio_get_direction() function is called from
gpiod_get_direction(), which ends up being used within the __setup_irq()
call stack when requesting an interrupt.

__setup_irq() holds a raw_spinlock_t with IRQs disabled, which creates
an atomic context. spinlock_t cannot be used within atomic context
when PREEMPT_RT is enabled, since it may become a sleeping lock.

An "[ BUG: Invalid wait context ]" splat is observed when running with
CONFIG_PROVE_LOCKING enabled, describing exactly the aforementioned call
stack.

__setup_irq() needs to hold a raw_spinlock_t with IRQs disabled to
serialize access against a concurrent hard interrupt.

Switch to raw_spinlock_t to fix this.

Fixes: 829dde3369a9 ("pinctrl: renesas: rzt2h: Add GPIO IRQ chip to handle interrupts")
Signed-off-by: Cosmin Tanislav <cosmin-gabriel.tanislav.xa@renesas.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260205103930.666051-1-cosmin-gabriel.tanislav.xa@renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>