bna: Replace large udelay() with mdelay()

udelay() does not work on some architectures for values above
2000, in particular on ARM:

ERROR: "__bad_udelay" [drivers/net/ethernet/brocade/bna/bna.ko] undefined!
Reported-by: NVagrant Cascadian <vagrant@debian.org>
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/brocade/bna/bfa_ioc.c

@@ -1704,7 +1704,7 @@ bfa_flash_sem_get(void __iomem *bar)
 	while (!bfa_raw_sem_get(bar)) {
 		if (--n <= 0)
 			return BFA_STATUS_BADFLASH;
-		udelay(10000);
+		mdelay(10);
 	}
 	return BFA_STATUS_OK;
 }