scripts/dtc: Revert "yamltree: Ensure consistent bracketing of properties with phandles"

This reverts upstream commit 18d7b2f4ee45fec422b7d82bab0b3c762ee907e4. A
revert in upstream dtc is pending.

This commit didn't work for properties such as 'interrupt-map' that have
phandle in the middle of an entry. It would also not work for a 0 or -1
phandle value that acts as a NULL.

Signed-off-by: Rob Herring <robh@kernel.org>