clk: imx: pll14xx: fix recalc_rate for negative kdiv

kdiv is a signed 16 bit value in the DEV_CTL1 register. Commit
53990cf ("clk: imx: pll14xx: consolidate rate calculation") changed
the kdiv variable from a short int to just int. When the value read from
the DIV_CTL1 register is assigned directly to an int the sign of the value
is lost resulting in incorrect results when the value is negative. Adding
a s16 cast to the register value fixes the issue.

Fixes: 53990cf ("clk: imx: pll14xx: consolidate rate calculation")
Signed-off-by: Kevin Groeneveld <kgroeneveld@lenbrook.com>
Link: https://lore.kernel.org/r/20221210203835.9714-1-kgroeneveld@lenbrook.com
Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Author: Kevin Groeneveld

drivers/clk/imx/clk-pll14xx.c

@@ -256,7 +256,7 @@ static unsigned long clk_pll14xx_recalc_rate(struct clk_hw *hw,
 
 	if (pll->type == PLL_1443X) {
 		pll_div_ctl1 = readl_relaxed(pll->base + DIV_CTL1);
-		kdiv = FIELD_GET(KDIV_MASK, pll_div_ctl1);
+		kdiv = (s16)FIELD_GET(KDIV_MASK, pll_div_ctl1);
 	} else {
 		kdiv = 0;
 	}