[Why & How]
 - Remove tick count definition since it can be different
   per HW revision
Acked-by: NQingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: NAnthony Koo <Anthony.Koo@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>