Blackfin arch: Allow a gpio pin be requested both as gpio and irq.

[Mike Frysinger <vapier.adi@gmail.com>:
 - use KERN_NOTICE when using gpios as both irq and non
   rather than KERN_ERR
 - embedded newlines in printk() does not fly]

Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>