stm32f7: enable existing exti headers

include/libopencm3/stm32/exti.h

@@ -32,6 +32,8 @@
 #       include <libopencm3/stm32/f3/exti.h>
 #elif defined(STM32F4)
 #       include <libopencm3/stm32/f4/exti.h>
+#elif defined(STM32F7)
+#       include <libopencm3/stm32/f7/exti.h>
 #elif defined(STM32L0)
 #       include <libopencm3/stm32/l0/exti.h>
 #elif defined(STM32L1)

include/libopencm3/stm32/f7/exti.h

@@ -0,0 +1,33 @@
+/** @defgroup exti_defines EXTI Defines
+ *
+ * @brief <b>Defined Constants and Types for the STM32F7xx External Interrupts
+ * </b>
+ *
+ * @ingroup STM32F7xx_defines
+ *
+ * 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_EXTI_H
+#define LIBOPENCM3_EXTI_H
+
+#include <libopencm3/stm32/common/exti_common_all.h>
+#include <libopencm3/stm32/common/exti_common_v1.h>
+
+#endif