esp32s2: IRAM/DRAM memory protection

* new mem_prot API
* mem_prot on & locked by default (see Kconfig)
* feature activated in start_cpu0_default()

JIRA IDF-1355

components/esp32/include/esp32/cache_err_int.h

@@ -17,7 +17,7 @@
  * @brief initialize cache invalid access interrupt
  *
  * This function enables cache invalid access interrupt source and connects it
- * to interrupt input number ETS_CACHEERR_INUM (see soc/soc.h). It is called
+ * to interrupt input number ETS_MEMACCESS_ERR_INUM (see soc/soc.h). It is called
  * from the startup code.
  */
 void esp_cache_err_int_init(void);