mvebu: armada-37xx: add patch to forbid cpufreq for 1.2 GHz

mvebu: armada-37xx: add patch to forbid cpufreq for 1.2 GHz

This patch is backported from linux-arm-kernel [1] to improve situation, when
it was reported that 1.2 GHz variant is unstable with DFS.
It waits to be accepted upstream, however, it waits for Marvell people to respond.

[1] https://patchwork.kernel.org/project/linux-arm-kernel/patch/20210630225601.6372-1-kabel@kernel.org/

Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>
(cherry picked from commit d3794768177293f584cc74f90c921276793da1e7)