staging: mt7621-dts: remove 'gdma' and 'hsdma' nodes

Drivers related with 'gdma' and 'hsdma' nodes are not in-tree. Remove them
from the device tree file.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20211113192045.32153-4-sergio.paracuellos@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>