drm/amdkfd: Increase vcrat size for GPU

GPU cache info (part of virtual CRAT) size depends on CU number.
For arcturus, CU number has been increased. So the required memory
for vcrat also increases.

Signed-off-by: Oak Zeng <Oak.Zeng@amd.com>
Reviewed-by: Yong Zhao <Yong.Zhao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>