clk: rockchip: rk3588: fix indent

pclk_mailbox2 is the only RK3588 clock indented with one tab instead of
two tabs. Let's fix this.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20240126182919.48402-6-sebastian.reichel@collabora.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>