[mlir][spirv] Fix capability check for 64-bit element types

Using 64-bit integer/float type in interface storage classes would
require Int64/Float64 capability, per the Vulkan spec:

```
shaderInt64 specifies whether 64-bit integers (signed and unsigned) are
supported in shader code. If this feature is not enabled, 64-bit integer
types must not be used in shader code. This also specifies whether
shader modules can declare the Int64 capability. Declaring and using
64-bit integers is enabled for all storage classes that SPIR-V allows
with the Int64 capability.
```

This is different from, say, 16-bit element types, where:

```
shaderInt16 specifies whether 16-bit integers (signed and unsigned) are
supported in shader code. If this feature is not enabled, 16-bit integer
types must not be used in shader code. This also specifies whether
shader modules can declare the Int16 capability. However, this only
enables a subset of the storage classes that SPIR-V allows for the Int16
SPIR-V capability: Declaring and using 16-bit integers in the Private,
Workgroup (for non-Block variables), and Function storage classes is
enabled, while declaring them in the interface storage classes (e.g.,
UniformConstant, Uniform, StorageBuffer, Input, Output, and
PushConstant) is not enabled.
```

Reviewed By: hanchung

Differential Revision: https://reviews.llvm.org/D126256