[bsp][stm32] update drv_lcd

bsp/stm32/README.md

@@ -16,6 +16,7 @@ STM32 系列 BSP 目前支持情况如下表所示：
 | [stm32f429-atk-apollo](stm32f429-atk-apollo/)      | 正点原子 F429 阿波罗开发板 |
 | [stm32f429-fire-challenger](stm32f429-fire-challenger/) | 野火 F429 挑战者开发板     |
 | [stm32f429-armfly-v6](stm32f429-armfly-v6) | 安富莱 f429-v6 开发板 |
+| [stm32f446-st-nucleo](stm32f446-st-nucleo) | ST 官方 stm32f446-nucleo 开发板 |
 | **F7 系列** |  |
 | [stm32f767-atk-apollo](stm32f767-atk-apollo) | 正点原子 F767 阿波罗开发板 |
 | [stm32f767-fire-challenger](stm32f767-fire-challenger/) | 野火 F767 挑战者开发板 |

bsp/stm32/libraries/HAL_Drivers/drv_lcd.c

@@ -244,10 +244,10 @@ void turn_on_lcd_backlight(void)
     struct rt_device_pwm *pwm_dev;
 
     /* turn on the LCD backlight */
-    pwm_dev = (struct rt_device_pwm *)rt_device_find(PWM_DEV_NAME);
+    pwm_dev = (struct rt_device_pwm *)rt_device_find(LCD_PWM_DEV_NAME);
     /* pwm frequency:100K = 10000ns */
-    rt_pwm_set(pwm_dev, PWM_DEV_CHANNEL, 10000, 10000);
-    rt_pwm_enable(pwm_dev, PWM_DEV_CHANNEL);
+    rt_pwm_set(pwm_dev, LCD_PWM_DEV_CHANNEL, 10000, 10000);
+    rt_pwm_enable(pwm_dev, LCD_PWM_DEV_CHANNEL);
 }
 #elif defined(LCD_BACKLIGHT_USING_GPIO)
 void turn_on_lcd_backlight(void)