rust: driver: Consolidate `Adapter::of_id_info` methods using `#[cfg]`

rust: driver: Consolidate `Adapter::of_id_info` methods using `#[cfg]`

Refactor the `of_id_info` methods in the `Adapter` trait to reduce
duplication. Previously, the method had two versions selected
via `#[cfg(...)]` and `#[cfg(not(...))]`. This change merges them into a
single method by using `#[cfg]` blocks within the method body.

Suggested-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://lore.kernel.org/r/20250620153656.294468-1-igor.korotin.linux@gmail.com
[ Fix clippy warning if #[cfg(not(CONFIG_OF))]; fix checkpatch.pl line
  length warnings. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>