ARM: OMAP2+: Add missing put_device() call in omapdss_init_of()

ARM: OMAP2+: Add missing put_device() call in omapdss_init_of()

A coccicheck run provided information like the following.

arch/arm/mach-omap2/display.c:268:2-8: ERROR: missing put_device;
call of_find_device_by_node on line 258, but without a corresponding
object release within this function.

Generated by: scripts/coccinelle/free/put_device.cocci

Thus add the missed function call to fix the exception handling for
this function implementation.

Fixes: e0c827aca0730b51f38081aa4e8ecf0912aab55f ("drm/omap: Populate DSS children in omapdss driver")
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>