clk: SPEAr: Vco-pll: Fix compilation warning

Currently we are getting following warning for SPEAr clk-vco-pll.

"warning: i is used uninitialized in this function."

This is because we are getting value of i by passing its pointer to another
routine.

The variables here are really not used uninitialized.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>