drm/amdgpu: use job and ib structures directly in CS parsers

Instead of providing the ib index provide the job and ib pointers directly to
the patch and parse functions for UVD and VCE.

Also move the set/get functions for IB values to the IB declerations.

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>