MdePkg/AArch64: Fixed some definitions in ProcessorBind.h

- Fixed INT8 declaration
- Introduced MAX_INTN/MAX_UINTN
- Force the MAX_* to be 'unsigned long long' numbers

Change-Id: I1ad818559d051df9a880aa8e4ac090e76fdb27e0
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>



git-svn-id: svn://svn.code.sf.net/p/edk2/code/trunk/edk2/MdePkg@14610 6f19259b-4bc3-4df7-8a09-765794883524