msm: clock-debug: Update fmax_rates to print uV/uA values for each level

Example output after change:
/sys/kernel/debug/clk/a7sspll $ cat fmax_rates
                  reg 0     reg 1
         freq        uV        uV
            0         0         1
   1000000000   1800000         4
 [ 1900000000   1800000         5]
            0   1800000         7

Change-Id: I1563cd8f77d479e0c6c67ee3c93a66fbafb6d6f7
Signed-off-by: Xiaogang Cui <xiaogang@codeaurora.org>