clk: mediatek: fix of_iomap memory leak

clk: mediatek: fix of_iomap memory leak

Smatch reports:
drivers/clk/mediatek/clk-mtk.c:583 mtk_clk_simple_probe() warn:
    'base' from of_iomap() not released on lines: 496.

This problem was also found in linux-next. In mtk_clk_simple_probe(),
base is not released when handling errors
if clk_data is not existed, which may cause a leak.
So free_base should be added here to release base.

Fixes: c58cd0e40ffa ("clk: mediatek: Add mtk_clk_simple_probe() to simplify clock providers")
Signed-off-by: Bosi Zhang <u201911157@hust.edu.cn>
Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
Link: https://lore.kernel.org/r/20230422084331.47198-1-u201911157@hust.edu.cn
Signed-off-by: Stephen Boyd <sboyd@kernel.org>