IntelSiliconPkg: Identify flash regions by GUID

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



Adds a new SPI 2 protocol (and corresponding PPI) that identify
flash regions by GUID instead of fixed values defined in an enum.

Packages consuming IntelSiliconPkg are able to associate a given
GUID with their chosen values based on their SPI flash details as
implemented in their PCH_SPI2_PROTOCOL instance.

Cc: Ray Ni <ray.ni@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: Sai Chaganty <rangasai.v.chaganty@intel.com>
Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com>