ARM: OMAP2+: Fix refcount leak in omapdss_init_of

omapdss_find_dss_of_node() calls of_find_compatible_node() to get device
node. of_find_compatible_node() returns a node pointer with refcount
incremented, we should use of_node_put() on it when done.
Add missing of_node_put() in later error path and normal path.

Fixes: e0c827ac ("drm/omap: Populate DSS children in omapdss driver")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Message-Id: <20220601044858.3352-1-linmq006@gmail.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>