ARM: dts: imx7d: remove "operating-points" property for cpu1

Commit b97872d4 ("ARM: dts: imx: Add missing OPP properties for CPUs")
added "operating-points" property for all CPUs, but i.MX7D already has
"operating-points-v2" property on both CPUs, so no need to add
"operating-points" property again, this patch removes it.

Fixes: b97872d4 ("ARM: dts: imx: Add missing OPP properties for CPUs")
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>