boards/esp32: UART configuration approach changed

UART devices are now configured using static array in header files instead of static variables in implementation to be able to define UART_NUMOF using the size of the array instead of a variable.

boards/common/esp32/include/periph_conf_common.h

@@ -139,6 +139,35 @@ extern "C" {
  * @name   UART configuration
  */
 
+#ifndef UART0_TXD
+#define UART0_TXD   (GPIO1)  /**< TxD of UART_DEV(0) used on all ESP32 boards */
+#endif
+#ifndef UART0_RXD
+#define UART0_RXD   (GPIO3)  /**< RxD of UART_DEV(0) used on all ESP32 boards */
+#endif
+
+/**
+ * @brief   Static array with configuration for declared I2C devices
+ */
+static const uart_conf_t uart_config[] = {
+    {
+        .txd = UART0_TXD,
+        .rxd = UART0_RXD,
+    },
+    #if defined(UART1_TXD) && defined(UART1_RXD)
+    {
+        .txd = UART1_TXD,
+        .rxd = UART1_RXD,
+    },
+    #endif
+    #if defined(UART2_TXD) && defined(UART2_RXD)
+    {
+        .txd = UART2_TXD,
+        .rxd = UART2_RXD,
+    },
+    #endif
+};
+
 /**
  * @brief Number of UART interfaces
  *