clk: clock-alpha-pll: Always setup PLL configuration

If a PLL is turned on by the boot chain in an unexpected
configuration, it will always remain in that configuration.
However, implementations may depend on the PLL being in the
right configuration the next time that it is enabled.

Change-Id: If0ee1e040e4a1fbb71a236fac5178509d3d33dc6
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>