ARM: dts: silk: Correct clock of DU1

ARM: dts: silk: Correct clock of DU1

[ Upstream commit 403fe77e22eb72c962c3889efc9d4fa62e454737 ]

The second channel of the display unit uses a different module clock
than the first channel.

Fixes: 84e734f497cd48f6 ("ARM: dts: silk: add DU DT support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>