fix(c0): missing GPIO_AF0_USART2 for STM32C051xx

See STMicroelectronics/stm32c0xx-hal-driver#4

Signed-off-by: Nessotrin <nessotrin@hotmail.fr>
Co-authored-by: Frederic Pillon <frederic.pillon@st.com>

Author: nessotrin

libraries/SrcWrapper/inc/stm32_def.h

@@ -222,9 +222,14 @@ __STATIC_INLINE void LL_RTC_SetBinMixBCDU(RTC_TypeDef *RTCx, uint32_t BinMixBcdU
   #define GPIO_AF1_SPI1 STM_PIN_AFNUM_MASK
 #endif
 
-#if defined(STM32C0xx) && defined(USART3) && !defined(GPIO_AF7_USART3)
-  #define GPIO_AF7_USART3 ((uint8_t)0x07)
-#endif // STM32C0xx && !defined(USART3)
+#if defined(STM32C0xx)
+  #if defined(USART3) && !defined(GPIO_AF7_USART3)
+    #define GPIO_AF7_USART3 ((uint8_t)0x07)
+  #endif /* USART3 & !GPIO_AF7_USART3*/
+  #if defined(STM32C051xx) && !defined(GPIO_AF0_USART2)
+    #define GPIO_AF0_USART2 ((uint8_t)0x00)
+  #endif
+#endif // STM32C0xx
 
 #if defined(STM32WBAxx) && defined(USB_OTG_HS) && !defined(GPIO_AF4_USB_OTG_HS)
   #define GPIO_AF4_USB_OTG_HS GPIO_AF4_OTG_HS

system/Drivers/STM32C0xx_HAL_Driver/Inc/stm32c0xx_hal_gpio_ex.h

@@ -61,7 +61,7 @@ extern "C" {
 #define GPIO_AF0_OSC           ((uint8_t)0x00)  /*!< OSC (By pass and Enable) Alternate Function mapping */
 #define GPIO_AF0_TIM14         ((uint8_t)0x00)  /*!< TIM14 Alternate Function mapping */
 #endif /* !STM32C011xx */
-#if defined(STM32C031xx) || defined(STM32C071xx) || defined(STM32C091xx)  || defined(STM32C092xx)
+#if defined(STM32C031xx) || defined(STM32C051xx) || defined(STM32C071xx) || defined(STM32C091xx)  || defined(STM32C092xx)
 #define GPIO_AF0_USART2        ((uint8_t)0x00)  /*!< USART2 Alternate Function mapping */
 #endif /* STM32C031xx | STM32C071xx | STM32C091xx | STM32C092xx*/
 #if defined(SPI2)