lib: Add Atmel SAM3x8e ARM CMSIS files

Add the ARM CMSIS definitions (obtained from an Arduino copy of
libsam) in preparation for Arduino Due support.

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

lib/cmsis-sam3x8e/include/system_sam3xa.h

@@ -0,0 +1,58 @@
+/*! \file *********************************************************************
+ *
+ * \brief CMSIS Cortex-M# Device Peripheral Access Layer Header File
+ *           for SAM3 devices.
+ *
+ * $asf_license$
+ *
+ * \par Purpose
+ *
+ * This file provides basic support for Cortex-M processor based 
+ * microcontrollers.
+ *
+ * \author               Atmel Corporation: http://www.atmel.com \n
+ *                       Support and FAQ: http://support.atmel.no/
+ *
+ ******************************************************************************/
+
+#ifndef SYSTEM_SAM3X_H_INCLUDED
+#define SYSTEM_SAM3X_H_INCLUDED
+
+/* @cond 0 */
+/**INDENT-OFF**/
+#ifdef __cplusplus
+extern "C" {
+#endif
+/**INDENT-ON**/
+/* @endcond */
+
+#include <stdint.h>
+
+extern uint32_t SystemCoreClock;	/* System Clock Frequency (Core Clock) */
+
+/**
+ * @brief Setup the microcontroller system.
+ * Initialize the System and update the SystemCoreClock variable.
+ */
+void SystemInit(void);
+
+/**
+ * @brief Updates the SystemCoreClock with current core Clock 
+ * retrieved from cpu registers.
+ */
+void SystemCoreClockUpdate(void);
+
+/** 
+ * Initialize flash.
+ */
+void system_init_flash(uint32_t dw_clk);
+
+/* @cond 0 */
+/**INDENT-OFF**/
+#ifdef __cplusplus
+}
+#endif
+/**INDENT-ON**/
+/* @endcond */
+
+#endif /* SYSTEM_SAM3X_H_INCLUDED */