clk: qcom: clk-alpha: Reconfigure Alpha PLL during enable

During enable read the L value to determine if the configuration
is required again, otherwise the PLL would fail to lock or enable due to
lost/missing values.

Change-Id: I52e405daba45c6e8412c866515b8710ae2b077ea
Signed-off-by: Veera Vegivada <vvegivad@codeaurora.org>