thermal: nct72: report correct initial temperature

thermal: nct72: report correct initial temperature

If NCT is in standby mode, need to initiate one-shot conversion
before reading temperature, otherwise while bootup NCT will report
wrong initial temperature and driver will set wrong temperature
alert limits based on that.

Bug 200161159

Change-Id: I158a73eb692a71c0262496369bcd3bd3d62a40e1
Signed-off-by: Rajkumar Kasirajan <rkasirajan@nvidia.com>
(cherry picked from commit 4164770df219bcd37ffa68950882564181a78e8f)
Reviewed-on: http://git-master/r/929897
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Winnie Hsu <whsu@nvidia.com>