drm/amdkfd: Add PM4 target XCC

In a device that supports multiple XCCs, unlike AQL queues, the PM4 queue
will be only processed in one XCC in the partitioning. This patch
re-purposes the queue percentage variable in create queue and update
queue ioctl for the user space to specify the target XCC.

Signed-off-by: Amber Lin <Amber.Lin@amd.com>
Signed-off-by: Mukul Joshi <mukul.joshi@amd.com>
Tested-by: Amber Lin <Amber.Lin@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>