clk: qcom: clk-alpha-pll: Replace hw->init in PLL code

The hw->init is no longer valid after the HW clock is registered with
the clock framework, thus clean up the clock enable/disable. While at it
update the list register offset.

Change-Id: I965cd1d5c14efd2bea8cc220f2b19ed1f3ddfb8c
Signed-off-by: Taniya Das <tdas@codeaurora.org>