OvmfPkg: Copy Legacy8259 protocol definitions from IntelFrameworkPkg

OvmfPkg: Copy Legacy8259 protocol definitions from IntelFrameworkPkg

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1496

This commit copies the exact Legacy8259 protocol header file from
IntelFrameworkPkg to OvmfPkg. Also, the protocol GUID definition is
duplicated in the OvmfPkg DEC file.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Ray Ni <ray.ni@intel.com>
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>