The PalLib is IPF specific and will be removed from MdePkg.
So this patch removes PalLib in SignedCapsulePkg.dsc which was missed
at 52664c5252.
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Chen A Chen <chen.a.chen@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>