IntelSiliconPkg: Remove SPI v1 PPI and Protocol definitions

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3717



V2 of the PCH SPI PPI and PCH SPI Protocol were recently added to
IntelSiliconPkg. This change removes the v1 definitions.

V2 is intended to better support multiple silicon generations which
aligns with the goals of IntelSiliconPkg.

Cc: Ray Ni <ray.ni@intel.com>
Cc: Rangasai V Chaganty <rangasai.v.chaganty@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Isaac Oram <isaac.w.oram@intel.com>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com>
Reviewed-by: Sai Chaganty <rangasai.v.chaganty@intel.com>