clk: rockchip: Fix static checker warning in rockchip_ddrclk_get_parent call

Fixes the signedness bug returning '(-22)' on the return type by removing the
sanity checker in rockchip_ddrclk_get_parent(). The function should return
and unsigned value only and it's safe to remove the sanity checker as the
core functions that call get_parent like clk_core_get_parent_by_index already
ensures the validity of the clk index returned (index >= core->num_parents).

Fixes: a4f182bf81f18 ("clk: rockchip: add new clock-type for the ddrclk")
Cc: stable@vger.kernel.org
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

drivers/clk/rockchip/clk-ddr.c

@@ -80,16 +80,12 @@ static long rockchip_ddrclk_sip_round_rate(struct clk_hw *hw,
 static u8 rockchip_ddrclk_get_parent(struct clk_hw *hw)
 {
 	struct rockchip_ddrclk *ddrclk = to_rockchip_ddrclk_hw(hw);
-	int num_parents = clk_hw_get_num_parents(hw);
 	u32 val;
 
 	val = clk_readl(ddrclk->reg_base +
 			ddrclk->mux_offset) >> ddrclk->mux_shift;
 	val &= GENMASK(ddrclk->mux_width - 1, 0);
 
-	if (val >= num_parents)
-		return -EINVAL;
-
 	return val;
 }