Revert "of: reserved-memory: Fix using wrong number of cells to get property 'alignment'"

commit 75f1f311d883dfaffb98be3c1da208d6ed5d4df9 upstream.

This reverts commit 267b21d0bef8e67dbe6c591c9991444e58237ec9.

Turns out some DTs do depend on this behavior. Specifically, a
downstream Pixel 6 DT. Revert the change at least until we can decide if
the DT spec can be changed instead.

Cc: stable@vger.kernel.org
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>