ARM: imx: add missing clk_disable_unprepare()

commit f07ec85365807b3939f32d0094a6dd5ce065d1b9 upstream.

clock source is prepared and enabled by clk_prepare_enable()
in probe function, but no disable or unprepare in remove and
error path.

Fixes: 9454a0caff6a ("ARM: imx: add mmdc ipg clock operation for mmdc")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Nobuhiro Iwamatsu (CIP) <nobuhiro1.iwamatsu@toshiba.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>