Thermal: fix bug of counting cpu frequencies.

In the while loop for counting cpu frequencies, if table[i].frequency equals
CPUFREQ_ENTRY_INVALID, index i won't be increased, so this leads to an endless
loop, what's more the index i cannot be referred as cpu frequencies number if
there is CPUFREQ_ENTRY_INVALID case.

Signed-off-by: hongbo.zhang <hongbo.zhang@linaro.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Amit Daniel Kachhap <amit.kachhap@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>