MIPS: loongson32: Update the clock initialization

The Loongson-1 clock driver is under re-implementation
to add DT support. As a result, ls1x_clk_init() will be dropped soon.
Therefore, call of_clk_init() for clock initialization instead.

Signed-off-by: Keguang Zhang <keguang.zhang@gmail.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Link: https://lore.kernel.org/r/20230321111817.71756-5-keguang.zhang@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>