[ Upstream commit 0efcc2c0fd2001a83240a8c3d71f67770484917e ]

Same as other i.MX6 SoCs, ensure unused MMDC channel's
handshake is bypassed, this is to make sure no request
signal will be generated when periphe_clk_sel is changed
or SRC warm reset is triggered.
Signed-off-by: NAnson Huang <Anson.Huang@nxp.com>
Signed-off-by: NStephen Boyd <sboyd@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>