[mlir][spirv] Correctly deduce PhysicalStorageBuffer64 addressing model

According to the SPIR-V specification[1], PhysicalStorageBuffer storage
class can only be used iff addressing model is PhysicalStorageBuffer64.

[1]: https://www.khronos.org/registry/SPIR-V/specs/unified1/SPIRV.html#_addressing_model

Reviewed By: antiagainst

Differential Revision: https://reviews.llvm.org/D127067