Maintainers.txt: Remove maintainer info for IntelFsp[Wrapper]Pkg

Maintainers.txt: Remove maintainer info for IntelFsp[Wrapper]Pkg

We removed IntelFspPkg and IntelFspWrapperPkg for
<https://bugzilla.tianocore.org/show_bug.cgi?id=1819>; now remove
the dangling maintainer/reviewer assignments too.

Signed-off-by: Ray Ni <ray.ni@intel.com>
Cc: Andrew Fish <afish@apple.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Reviewed-by: Chasel Chiu <chasel.chiu@intel.com>