BaseTools: Override Max size by build Option Pcd for HII type

Current code will generate maxsize for HII type PCD when parser DSC
file, while this HII type PCD value maybe override in build command
per --pcd option, so the max size need re-calculate.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Yonghong Zhu <yonghong.zhu@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>