clk: sunxi: Add TCON channel1 clock

Hello Maxime Ripard,

The patch cc510c736b1b: "clk: sunxi: Add TCON channel1 clock" from Jul 1, 2015, leads to the following static checker warning:

	drivers/clk/sunxi/clk-sun4i-tcon-ch1.c:89 tcon_ch1_get_parent()
	warn: signedness bug returning '(-22)'

drivers/clk/sunxi/clk-sun4i-tcon-ch1.c
79 static u8 tcon_ch1_get_parent(struct clk_hw *hw)
^^
Is u8.

    80  {
    81          struct tcon_ch1_clk *tclk = hw_to_tclk(hw);
    82          int num_parents = clk_hw_get_num_parents(hw);
    83          u32 reg;
    84  
    85          reg = readl(tclk->reg) >> TCON_CH1_SCLK2_MUX_SHIFT;
    86          reg &= reg >> TCON_CH1_SCLK2_MUX_MASK;
    87  
    88          if (reg >= num_parents)
    89                  return -EINVAL;
                        ^^^^^^^^^^^^^^

Can't fit.

    90  
    91          return reg;
    92  }

regards,
dan carpenter