drm/msm/adreno: Use OPP for every GPU generation

Some older GPUs (namely a2xx with no opp tables at all and a320 with
downstream-remnants gpu pwrlevels) used not to have OPP tables. They
both however had just one frequency defined, making it extremely easy
to construct such an OPP table from within the driver if need be.

Do so and switch all clk_set_rate calls on core_clk to their OPP
counterparts.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/523784/
Link: https://lore.kernel.org/r/20230223-topic-opp-v3-3-5f22163cd1df@linaro.org
Signed-off-by: Rob Clark <robdclark@chromium.org>