MAINTAINERS: Add Akhil as a reviewer for the Adreno driver

MAINTAINERS: Add Akhil as a reviewer for the Adreno driver

Akhil should be getting tagged to review GPU patches.

Cc: Akhil P Oommen <akhilpo@oss.qualcomm.com>
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
Acked-by: Akhil P Oommen <akhilpo@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/685650/
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>