arm64: dts: uniphier: update to new Denali NAND binding

With commit d8e8fd0e ("mtd: rawnand: denali: decouple controller
and NAND chips"), the Denali NAND controller driver migrated to the
new controller/chip representation.

Update DT for it.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>