clk: sunxi: tcon-ch1: Do not return a negative error in get_parent

get_parent is supposed to return an unsigned 8 bit integer, so returning
-EINVAL is a bad idea.

Remove it.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

drivers/clk/sunxi/clk-sun4i-tcon-ch1.c

@@ -85,9 +85,6 @@ static u8 tcon_ch1_get_parent(struct clk_hw *hw)
 	reg = readl(tclk->reg) >> TCON_CH1_SCLK2_MUX_SHIFT;
 	reg &= reg >> TCON_CH1_SCLK2_MUX_MASK;
 
-	if (reg >= num_parents)
-		return -EINVAL;
-
 	return reg;
 }