BaseTools MemoryProfileSymbolGen.py: Handle 64bits rva from "nm -l xxx.dll"

BaseTools MemoryProfileSymbolGen.py: Handle 64bits rva from "nm -l xxx.dll"

Current MemoryProfileSymbolGen.py assumes the rva is 32bits,
the patch is to remove the restriction to match any lengths
of rva.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>