i.MX6ul: Fix bad printf format specifiers

We should use printf format specifier "%u" instead of "%d" for
argument of type "unsigned int".

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Alex Chen <alex.chen@huawei.com>
Message-id: 20201126111109.112238-5-alex.chen@huawei.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/misc/imx6ul_ccm.c

@@ -143,7 +143,7 @@ static const char *imx6ul_ccm_reg_name(uint32_t reg)
     case CCM_CMEOR:
         return "CMEOR";
     default:
-        sprintf(unknown, "%d ?", reg);
+        sprintf(unknown, "%u ?", reg);
         return unknown;
     }
 }
@@ -274,7 +274,7 @@ static const char *imx6ul_analog_reg_name(uint32_t reg)
     case USB_ANALOG_DIGPROG:
         return "USB_ANALOG_DIGPROG";
     default:
-        sprintf(unknown, "%d ?", reg);
+        sprintf(unknown, "%u ?", reg);
         return unknown;
     }
 }