drm/msm/adreno: Add A305B support

Add support for the Adreno 305B GPU that is found in MSM8226(v2) SoC.
Previously this was mistakenly claimed to be supported but using wrong
a configuration.

In MSM8226v1 there's also a A305B but with chipid 0x03000510 which
should work with the same configuration but due to lack of hardware for
testing this is not added.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Reviewed-by: David Heidelberg <david@ixit.cz>
Patchwork: https://patchwork.freedesktop.org/patch/575274/


Signed-off-by: Rob Clark <robdclark@chromium.org>