Begin to consolidate of_device.c

This moves all the common parts for the Sparc, Sparc64 and PowerPC
of_device.c files into drivers/of/device.c.

Apart from the simple move, Sparc gains of_match_node() and a call to
of_node_put in of_release_dev().  PowerPC gains better recovery if
device_create_file() fails in of_device_register().

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>