of/device: Move struct of_device define outside of CONFIG_OF_DEVICE test

Some code uses of_device even when CONFIG_OF_DEVICE is not set.  This
patch makes of_device valid all the time by moving it outside of the
ifdef CONFIG_OF_DEVICE test.

Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>