of: overlay: validate overlay properties #address-cells and #size-cells

commit 6f75118800acf77f8ad6afec61ca1b2349ade371 upstream.

If overlay properties #address-cells or #size-cells are already in
the live devicetree for any given node, then the values in the
overlay must match the values in the live tree.

If the properties are already in the live tree then there is no
need to create a changeset entry to add them since they must
have the same value.  This reduces the memory used by the
changeset and eliminates a possible memory leak.

Tested-by: Alan Tull <atull@kernel.org>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>