drm/amdkfd: Add 64-bit doorbell and wptr support to kernel queue

v2: Removed redundant 0x before %p.

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>