parisc: use arch_spinlock_t instead of raw_spinlock_t in irqstacks

parisc: use arch_spinlock_t instead of raw_spinlock_t in irqstacks

We need to use arch_spinlock_t spinlocks instead of raw_spinlock_t
spinlocks for irqstack protection else we will hit the "trylock failure
on UP" error message with CONFIG_SMP=n and CONFIG_DEBUG_SPINLOCK=y.

Since we can be called recursive here even on UP (we are in the irq
handler which handles even irq bh) this spinlock error message is just
wrong.

Signed-off-by: Helge Deller <deller@gmx.de>