sparc32, leon: APBUART driver must use archdata to get IRQ number

See Commit id 1636f8ac (sparc/of:
Move of_device fields into struct pdev_archdata), this patch
is similar to 19e4875f (of/sparc:
fix build regression from of_device changes)

Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>