Add missing PSRAM entry for Odroid (#467)

Author: Jason2866

boards/odroid_esp32.json

@@ -4,7 +4,7 @@
       "ldscript": "esp32_out.ld"
     },
     "core": "esp32",
-    "extra_flags": "-DARDUINO_ODROID_ESP32",
+    "extra_flags": "-DARDUINO_ODROID_ESP32 -DBOARD_HAS_PSRAM -mfix-esp32-psram-cache-issue",
     "f_cpu": "240000000L",
     "f_flash": "40000000L",
     "flash_mode": "dio",