drm/amd/display: update pixel clock params after stream slice count change in context

[why]
When ODM slice count is changed, otg master pipe's pixel clock params is
no longer valid as the value is dependent on ODM slice count.

Reviewed-by: Chaitanya Dhere <chaitanya.dhere@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>