drm/amdkfd: Update CWSR grace period for GFX9.4.3

For GFX9.4.3, setup a reduced default CWSR grace period equal to
1000 cycles instead of 64000 cycles.

Signed-off-by: Mukul Joshi <mukul.joshi@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>