ArmPkg/ArmDisassemblerLib: ARMThumb and AArch64 fixes

ArmPkg/ArmDisassemblerLib: ARMThumb and AArch64 fixes

- Fix ARM Thumb mask operator. This was flagged by a toolchain as warning
  "use of logical '&&' with constant operand [-Wconstant-logical-operand]"
- AArch64 should not be building the ARM32 disassemblers.
- Add a AArch64 build target. The disassembler is still to be
  implemented.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Harry Liebel <Harry.Liebel@arm.com>
Reviewed-by: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16069 6f19259b-4bc3-4df7-8a09-765794883524