drm/amdkfd: Use new struct for asic specific ops

This patch creates a new structure for asic specific operations, instead
of using the existing structure of operations.

This is done to make the code flow more logic, readable and maintainable.

The change is done only to the device queue manager module at this point.

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>