drm/amd/display: increase bb clock for DCN351

[Why and how]

Bounding box clocks for DCN351 should be increased as per request

Reviewed-by: Swapnil Patel <swapnil.patel@amd.com>
Acked-by: Wayne Lin <wayne.lin@amd.com>
Signed-off-by: Xi Liu <xi.liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>