clk qcom: clk-alpha-pll: Update to use determine rate ops for PLL

On 32 bit where the PLL requires to support the frequency beyond the range
of the `long int` the round rate ops cannot support. Thus update the
clk_ops to use determine rate instead.

While at it also fix the code in RCG.

Change-Id: I785c9a99d73255932d9ee465e637f6fa30239cd9
Signed-off-by: Taniya Das <tdas@codeaurora.org>