Revert "ASoC: atmel: Remove system clock tree configuration for at91sam9g20ek"

This reverts commit 6a20bf46 which is
commit c775cbf6

 upstream.

It is reported to cause problems, so drop it from the 5.4.y tree for now.

Link: https://lore.kernel.org/r/845b3053-d47b-4717-9665-79b120da133b@sirena.org.uk
Reported-by: Mark Brown <broonie@kernel.org>
Cc: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>