[bsp][stm32] Fix the warning when using ARM Compiler V6

bsp/stm32f20x/Libraries/CMSIS/CM3/DeviceSupport/ST/STM32F2xx/system_stm32f2xx.c

@@ -385,7 +385,7 @@ static void SetSysClock(void)
     RCC->CFGR |= RCC_CFGR_SW_PLL;
 
     /* Wait till the main PLL is used as system clock source */
-    while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS ) != RCC_CFGR_SWS_PLL);
+    while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS ) != RCC_CFGR_SWS_PLL)
     {
     }
   }

bsp/stm32f40x/Libraries/CMSIS/ST/STM32F4xx/Source/Templates/system_stm32f4xx.c

@@ -400,7 +400,7 @@ static void SetSysClock(void)
     RCC->CFGR |= RCC_CFGR_SW_PLL;
 
     /* Wait till the main PLL is used as system clock source */
-    while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS ) != RCC_CFGR_SWS_PLL);
+    while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS ) != RCC_CFGR_SWS_PLL)
     {
     }
   }