Edk2Platforms: Replace FatBinPkg with FatPkg

In order to remove FatBinPkg, relationships depend on
FatBinPkg need to be replaced by FatPkg in fdf. And
FatPkg needs to be added in dsc.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Shenglei Zhang <shenglei.zhang@intel.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Michael D Kinney <michael.d.kinney@intel.com>