clk: loongson1: Re-implement the clock driver

Re-implement the clock driver for Loongson-1 to
add devicetree support and fit into the clock framework.

Signed-off-by: Keguang Zhang <keguang.zhang@gmail.com>
Link: https://lore.kernel.org/r/20230321111817.71756-4-keguang.zhang@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>