DLTI: Simplifying getDevicePropertyValue API by returning Attribute type value (#96706)
**Rationale**
- With the current flexibility of supporting any type of value, we will
need to offer type-specific APIs to fetch a value (e.g.,
`getDevicePropertyValueAsInt` for integer type,
`getDevicePropertyValueAsFloat` for float type, etc.) A single type of
value will eliminate this need.
- Current flexibility can also lead to typing errors when a user fetches
the value of a property using an API that is not consistent with the
type of the value.
**What is the change**
For following system description,
```
module attributes {
dlti.target_system_spec = #dlti.target_system_spec<
"CPU": #dlti.target_device_spec<
#dlti.dl_entry<"max_vector_op_width", 64.0 : f32>>,
"GPU": #dlti.target_device_spec<
#dlti.dl_entry<"max_vector_op_width", 128 : ui32>>
>} {}
```
a user no longer needs to use `getDevicePropertyValueAsInt` for
retrieving GPU's `max_vector_op_width` and
`getDevicePropertyValueAsFloat` for retrieving CPU's
`max_vector_op_width`. Instead it can be done with a uniform API of
`getDevicePropertyValue`.