drm/amdkfd: Delete useless SDMA register setting on non HWS path

HW folks have confirm that we should not touch RESUME_CTX of
SDMA*_GFX_CONTEXT_CNTL when manipulating RLC queues.

Signed-off-by: Yong Zhao <Yong.Zhao@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>