Add OPT_MCU_SAME70 option value.

src/tusb_option.h

@@ -61,6 +61,7 @@
 #define OPT_MCU_SAME5X            203 ///< MicroChip SAM E5x
 #define OPT_MCU_SAMD11            204 ///< MicroChip SAMD11
 #define OPT_MCU_SAML22            205 ///< MicroChip SAML22
+#define OPT_MCU_SAME70            206 ///< MicroChip SAME70 series
 
 // STM32
 #define OPT_MCU_STM32F0           300 ///< ST STM32F0