ARM: omap2: Fix reference count leaks in omap_control_init()

ARM: omap2: Fix reference count leaks in omap_control_init()

The of_get_child_by_name() function increments the reference count
of child nodes, causing multiple reference leaks in omap_control_init():

1. scm_conf node never released in normal/error paths
2. clocks node leak when checking existence
3. Missing scm_conf release before np in error paths

Fix these leaks by adding proper of_node_put() calls and separate error
handling.

Fixes: e5b635742e98 ("ARM: OMAP2+: control: add syscon support for register accesses")
Cc: stable@vger.kernel.org
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
Reviewed-by: Andreas Kemnade <andreas@kemnade.info>
Link: https://patch.msgid.link/20251217142122.1861292-1-vulab@iscas.ac.cn
Signed-off-by: Kevin Hilman <khilman@baylibre.com>