ARM: dts: sunxi: nanopi: Remove input-name property

This property doesn't seem to exist in the documentation nor
in source code, but for some reason it is defined in a bunch
of device trees.

Signed-off-by: Dang Huynh <danct12@riseup.net>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20220425064231.243482-1-danct12@riseup.net