[SPARC64]: Fix type and constant sizes wrt. sun4u IMAP/ICLR handling.

Sometimes we were using 32-bit values and the top bits were
getting inadvertantly chopped off.  This will matter for the
forthcoming Fire controller MSI support.

Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc64/kernel/irq.c

@@ -308,7 +308,7 @@ static void sun4u_irq_disable(unsigned int virt_irq)
 
 	if (likely(data)) {
 		unsigned long imap = data->imap;
-		u32 tmp = upa_readq(imap);
+		unsigned long tmp = upa_readq(imap);
 
 		tmp &= ~IMAP_VALID;
 		upa_writeq(tmp, imap);