CoffeelakeSiliconPkg: Update for SPI2 PPI and Protocol

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3307



Updates references to the "PCH_SPI_PROTOCOL" and "PCH_SPI_PPI" to
instead refer to "PCH_SPI2_PROTOCOL" and "PCH_SPI2_PPI".

Cc: Chasel Chiu <chasel.chiu@intel.com>
Cc: Rangasai V Chaganty <rangasai.v.chaganty@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com>