Use imx_mmdc_mask_handshake() API instead of programming CCM
register directly in each platform to mask unused MMDC channel's
handshake.
Signed-off-by: NAnson Huang <Anson.Huang@nxp.com>
Reviewed-by: NDong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>