drm/imx: fix memory leak when fails to init

stable inclusion
from stable-5.10.28
commit 77a8e6f792d5cfca3c6a30845b069161647d1d55
bugzilla: 51779

--------------------------------

commit 69c3ed72 upstream.

Put DRM device on initialization failure path rather than directly
return error code.

Fixes: a67d5088 ("drm/imx: drop explicit drm_mode_config_cleanup")
Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by:   Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>