i2c: core: check if setting clock rate is allowed

i2c: core: check if setting clock rate is allowed

- In i2c_set_adapter_bus_clk_rate(), check if clock rate changing is
allowed.
- Use function i2c_set_adapter_bus_clk_rate to set the baud rate from
sysfs entry

Bug 1887805

Change-Id: I52be840090526c824e7f0e19f5acb5ab4c46a73d
Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
Reviewed-on: http://git-master/r/1462344
(cherry picked from commit ce43d0c575797d1096f6ccf6229c46ac0c72a36c)
Reviewed-on: https://git-master.nvidia.com/r/1589798
GVS: Gerrit_Virtual_Submit
Reviewed-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>