cpufreq: tegra194: Remove unnecessary frequency calculation

The Tegra194 CPUFREQ driver sets the CPUFREQ_NEED_INITIAL_FREQ_CHECK
flag which means that the CPUFREQ framework will call the 'get' callback
on boot to determine the current frequency of the CPUs. Therefore, it is
not necessary for the Tegra194 CPUFREQ driver to internally call the
tegra194_get_speed_common() during initialisation to query the current
frequency as well. Fix this by removing the call to the
tegra194_get_speed_common() during initialisation and simplify the code.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>