KabylakeSiliconPkg/PchPmcLib: Add GetSleepTypeAfterWakeup()

Adds the capability to get the system sleep type after wakeup to
PchPmcLib in KabylakeSiliconPkg.

This is needed by platforms to determine the Sx resume state.

Cc: Chasel Chiu <chasel.chiu@intel.com>
Cc: Sai Chaganty <rangasai.v.chaganty@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Benjamin Doron <benjamin.doron00@gmail.com>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com>
Reviewed-by: Chasel Chiu <chasel.chiu@intel.com>
Reviewed-by: Sai Chaganty <rangasai.v.chaganty@intel.com>