ARM: dts: imx7s: correct iomuxc gpr mux controller cells

stable inclusion
from stable-v5.10.173
commit e874629c5fb77ac1a09190f0c2352791f5f8e844
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8BFR3

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e874629c5fb77ac1a09190f0c2352791f5f8e844



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[ Upstream commit 0e3e1946 ]

Per binding doc reg-mux.yaml, the #mux-control-cells should be 1

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Fixes: 94a905a7 ("ARM: dts: imx7s: add multiplexer controls")
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>