ARM: dts: set 'ti,set-rate-parent' for dpll4_m5x2 clock

Set 'ti,set-rate-parent' property for the dpll4_m5x2_ck clock, which
is used for the ISP functional clock. This fixes the OMAP3 ISP driver's
clock rate configuration on OMAP34xx, which needs the rate to be
propagated properly to the divider node (dpll4_m5_ck).

Signed-off-by: Stefan Herbrechtsmeier <stefan@herbrechtsmeier.net>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: <linux-media@vger.kernel.org>
Cc: <linux-omap@vger.kernel.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>