cpu: imx8_cpu: Provide default temperatures

Add setting default temperatures to the weak version of
get_cpu_temp_grade so these values will not be used uninitialised.

This issue was found by Smatch.

Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>

drivers/cpu/imx8_cpu.c

@@ -201,6 +201,10 @@ static int cpu_imx_get_temp(struct cpu_imx_plat *plat)
 
 __weak u32 get_cpu_temp_grade(int *minc, int *maxc)
 {
+	if (minc && maxc) {
+		*minc = 0;
+		*maxc = 95;
+	}
 	return 0;
 }