drm/amdkfd: Fix L2 cache size reporting in GFX9.4.3

Its currently incorrectly multiplied by number of XCCs in the partition

Fixes: be457b22 ("drm/amdkfd: Update cache info for GFX 9.4.3")
Signed-off-by: Kent Russell <kent.russell@amd.com>
Reviewed-by: Mukul Joshi <mukul.joshi@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>