clk: move check for CLK_ENABLE_HAND_OFF at unused tree

The commit 04a0136aeea5 ("clk: introduce CLK_ENABLE_HAND_OFF flag")
assumes that the first time clock client calls a clk_prepare &
clk_enable, the clocks from that point of time could be on their own.
But there could be use cases which could have impacts due to this
handling. Moving the handoff counts for prepare and enable at unused
tree level.

Change-Id: I7d527571c2eb4d53d58d82126989bd673de12e2d
Signed-off-by: Taniya Das <tdas@codeaurora.org>