sparc32: convert to asm-generic/hardirq.h

From: Christoph Hellwig <hch@lst.de>

[akpm@linux-foundation.org: /arch/sparc/include/asm/irq_32.h: move NR_IRQS definition]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>