MIPS: Alchemy: Remove bogus args from alchemy_clk_fgcs_detr

They were added to this function by mistake when they were added to the
clk_ops.determine_rate callback.

Fixes: 1c8e600440c7 ("clk: Add rate constraints to clocks")
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>