drm/msm/a8xx: Fix the ticks used in submit traces

drm/msm/a8xx: Fix the ticks used in submit traces

GMU_ALWAYS_ON_COUNTER_* registers got moved in A8x, but currently, A6x
register offsets are used in the submit traces instead of A8x offsets.
To fix this, refactor a bit and use adreno_gpu->funcs->get_timestamp()
everywhere.

While we are at it, update a8xx_gmu_get_timestamp() to use the GMU AO
counter.

Fixes: 288a93200892 ("drm/msm/adreno: Introduce A8x GPU Support")
Signed-off-by: Akhil P Oommen <akhilpo@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/714655/
Message-ID: <20260327-a8xx-gpu-batch2-v2-2-2b53c38d2101@oss.qualcomm.com>
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>