i3c: dw: Add optional apb clock

Besides the core clock, IP also has an apb interface clock.
Add an optional hook for the same.

Signed-off-by: Aniket <aniketmaurya@google.com>
Link: https://lore.kernel.org/r/20240628154618.327151-1-aniketmaurya@google.com


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>