lib: Add Atmel SAMD51 cmsis files

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

lib/samd51/samd51a/include/instance/rstc.h

@@ -0,0 +1,48 @@
+/**
+ * \file
+ *
+ * \brief Instance description for RSTC
+ *
+ * Copyright (c) 2018 Microchip Technology Inc.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the Licence at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _SAMD51_RSTC_INSTANCE_
+#define _SAMD51_RSTC_INSTANCE_
+
+/* ========== Register definition for RSTC peripheral ========== */
+#if (defined(__ASSEMBLY__) || defined(__IAR_SYSTEMS_ASM__))
+#define REG_RSTC_RCAUSE            (0x40000C00) /**< \brief (RSTC) Reset Cause */
+#define REG_RSTC_BKUPEXIT          (0x40000C02) /**< \brief (RSTC) Backup Exit Source */
+#else
+#define REG_RSTC_RCAUSE            (*(RoReg8 *)0x40000C00UL) /**< \brief (RSTC) Reset Cause */
+#define REG_RSTC_BKUPEXIT          (*(RoReg8 *)0x40000C02UL) /**< \brief (RSTC) Backup Exit Source */
+#endif /* (defined(__ASSEMBLY__) || defined(__IAR_SYSTEMS_ASM__)) */
+
+/* ========== Instance parameters for RSTC peripheral ========== */
+#define RSTC_BACKUP_IMPLEMENTED     1       
+#define RSTC_HIB_IMPLEMENTED        1       
+#define RSTC_NUMBER_OF_EXTWAKE      0        // number of external wakeup line
+#define RSTC_NVMRST_IMPLEMENTED     1       
+
+#endif /* _SAMD51_RSTC_INSTANCE_ */