Remove zero address check in IoMmuMap. The reason is that a CSM legacy driver may use legacy memory for DMA. As such, the legacyBios need allow below 1M to the legacy device. This patch also fixed some typo. Cc: Star Zeng <star.zeng@intel.com> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Jiewen Yao <jiewen.yao@intel.com> Reviewed-by: Star Zeng <star.zeng@intel.com>