soc: qcom: use no-UBWC config for MSM8956/76

Both MSM8956 and MSM8976 have MDSS 1.11 which doesn't support UBWC
(although they also have Adreno 510, which might support UBWC). Disable
UBWC support for those platforms.

Fixes: 1924272b ("soc: qcom: Add UBWC config provider")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/668503/


Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>