Sandbox unit tests in U-Boot proper load a test device tree to have some
devices to work with. In order to do the same in SPL, we must enable
SPL_OF_REAL. However, we already have SPL_OF_PLATDATA enabled. When
generating platdata from a devicetree, it is expected that we will not need
devicetree access functions (even though SPL_OF_CONTROL is enabled). This
expectation does not hold for sandbox, so allow user control of
SPL_OF_REAL.

There are several places in the tree where conditions involving OF_PLATDATA
or OF_REAL no longer function correctly when both of these options can be
selected at the same time. Adjust these conditions accordingly.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>