clk: versaclock3: Use u8 return type for get_parent() callback

The return type of get_parent() member in struct clk_ops is u8.
Use same return type for corresponding callback function as well.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20231122142310.203169-4-biju.das.jz@bp.renesas.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>