KabylakeSiliconPkg: Add SPI write support in PEI

Adds a new library PeiSpiLib to perform the initialization necessary
to perform SPI write cycles in PEI. After initialization, it installs
an instance of the PCH_SPI_PPI.

Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Chasel Chiu <chasel.chiu@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Michael Kubacki <michael.a.kubacki@intel.com>
Reviewed-by: Chasel Chiu <chasel.chiu@intel.com>
Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com>