Revert "OPP: Protect dev_list with opp_table lock"

Revert "OPP: Protect dev_list with opp_table lock"

This reverts commit 714ab224a8db6e8255c61a42613de9349ceb0bba which is
commit 3d2556992a878a2210d3be498416aee39e0c32aa upstream.

Turns out to break the build on the odroid machines, so it needs to be
reverted.

Reported-by: Viresh Kumar <viresh.kumar@linaro.org>
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Cc: Niklas Cassel <niklas.cassel@linaro.org>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>