nrf: Set .mpy features consistent with documentation and other ports.

This allows nrf devices to load .mpy files.  And nrf52840 and nrf9160 based
boards also support compiling and loading native code.

ports/nrf/mpconfigdevice_nrf52840.h

@@ -34,6 +34,16 @@
 #define MICROPY_VFS                        (1)
 #endif
 
+// Board overridable emitter configuration.
+
+#ifndef MICROPY_EMIT_THUMB
+#define MICROPY_EMIT_THUMB          (1)
+#endif
+
+#ifndef MICROPY_EMIT_INLINE_THUMB
+#define MICROPY_EMIT_INLINE_THUMB   (1)
+#endif
+
 // Board overridable feature configuration.
 
 #ifndef MICROPY_ENABLE_SOURCE_LINE

ports/nrf/mpconfigdevice_nrf9160.h

@@ -34,6 +34,16 @@
 #define MICROPY_VFS                        (1)
 #endif
 
+// Board overridable emitter configuration.
+
+#ifndef MICROPY_EMIT_THUMB
+#define MICROPY_EMIT_THUMB          (1)
+#endif
+
+#ifndef MICROPY_EMIT_INLINE_THUMB
+#define MICROPY_EMIT_INLINE_THUMB   (1)
+#endif
+
 // Board overridable feature configuration.
 
 #ifndef MICROPY_ENABLE_SOURCE_LINE

ports/nrf/mpconfigport.h

@@ -43,7 +43,7 @@
 #define MICROPY_VFS                 (0)
 #endif
 #define MICROPY_ALLOC_PATH_MAX      (512)
-#define MICROPY_PERSISTENT_CODE_LOAD (0)
+#define MICROPY_PERSISTENT_CODE_LOAD (1)
 #define MICROPY_COMP_MODULE_CONST   (0)
 #define MICROPY_COMP_TRIPLE_TUPLE_ASSIGN (0)
 #define MICROPY_READER_VFS          (MICROPY_VFS)
@@ -103,7 +103,7 @@
 #define MICROPY_CAN_OVERRIDE_BUILTINS (1)
 #define MICROPY_USE_INTERNAL_ERRNO  (1)
 #define MICROPY_PY_FUNCTION_ATTRS   (1)
-#define MICROPY_PY_BUILTINS_STR_UNICODE (0)
+#define MICROPY_PY_BUILTINS_STR_UNICODE (1)
 #define MICROPY_PY_BUILTINS_STR_CENTER (0)
 #define MICROPY_PY_BUILTINS_STR_PARTITION (0)
 #define MICROPY_PY_BUILTINS_STR_SPLITLINES (0)