devicetree: Add empty of_platform_populate() for !CONFIG_OF_ADDRESS (sparc)

Sparc has its own helpers for translating address ranges when the device
tree is parsed at boot time, and it isn't able to use of_platform_populate().
However, there are some device drivers that want to use that function on
other DT enabled platforms (ie. TWL4030).  This patch adds an empty
of_platform_populate() implementation that returns an error when
CONFIG_OF_ADDRESS is not selected.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>