ramips: mt7621-dts: remove ethsys node

ramips: mt7621-dts: remove ethsys node

DT 'ethsys' node is being configured as a syscon
to get access to reset and other registers in the
'mediateķ,mt7621-eth' driver. Since the 'sysc' is also
a syscon, provides the clock and also is virtually
mapped from the same physical address 0x1e000000 we
can just use 'sysc' as the phandle for the syscon in
the ethernet node. Compatible string 'mediatek,mt7621-ethsys'
of the node is not being used anywhere inside the kernel
so, this node can be safely removed.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20210505132154.8263-2-sergio.paracuellos@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>