stm32g4: i2c: enable common peripheral code.

include/libopencm3/stm32/g4/i2c.h

@@ -0,0 +1,34 @@
+/** @defgroup i2c_defines I2C Defines
+ *
+ * @ingroup STM32G4xx_defines
+ *
+ * @brief <b>Defined Constants and Types for the STM32G4xx I2C</b>
+ *
+ * @version 1.0.0
+ *
+ * LGPL License Terms @ref lgpl_license
+ *  */
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef LIBOPENCM3_I2C_H
+#define LIBOPENCM3_I2C_H
+
+#include <libopencm3/stm32/common/i2c_common_v2.h>
+
+#endif
+

include/libopencm3/stm32/i2c.h

@@ -40,7 +40,8 @@
 #       include <libopencm3/stm32/l4/i2c.h>
 #elif defined(STM32G0)
 #       include <libopencm3/stm32/g0/i2c.h>
+#elif defined(STM32G4)
+#       include <libopencm3/stm32/g4/i2c.h>
 #else
 #       error "stm32 family not defined."
 #endif
-