KabylakeSiliconPkg/BaseSmbusLib: Fix SmBusSendByte value

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3451



Update SmBusSendByte() to write value to Command Register instead of
Host Data registers.

Cc: Chasel Chiu <chasel.chiu@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com>
Reviewed-by: Chasel Chiu <chasel.chiu@intel.com>