cpufreq: ti-cpufreq: Remove revision offsets in AM62 family

With the Silicon revision being taken directly from socinfo, there's no
longer any need for reading any SOC register for revision from this driver.
Hence, we do not require any rev_offset for AM62 family of devices.

Signed-off-by: Dhruva Gole <d-gole@ti.com>
Reviewed-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>