zephyr/mpconfigport: Use MICROPY_CONFIG_ROM_LEVEL_BASIC_FEATURES.

This commit adjusts the configuration of the standard zephyr build to use
MICROPY_CONFIG_ROM_LEVEL_BASIC_FEATURES.  That's a lot cleaner than
explicitly enabling/disabling options, and allows boards to more easily
fine-tune the settings, eg select a different feature level.

Features that are now enabled are:
- async/await keyword support
- `filter`, `property` and `reversed` builtins
- `range` attributes
- `str.count()` method
- `array` module with `array.array` object
- `collections` module with `collections.namedtuple` object
- `struct` module with everything
- `id = const()` and constant folding in the compiler

Bulding qemu_cortex_m3, the code size was originally:

    Memory region         Used Size  Region Size  %age Used
               FLASH:      193864 B       256 KB     73.95%
                 RAM:       61992 B        64 KB     94.59%

and with this commit it is now:

    Memory region         Used Size  Region Size  %age Used
               FLASH:      200698 B       256 KB     76.56%
                 RAM:       61992 B        64 KB     94.59%

That's a mild increase of +6834 bytes flash usage for a good selection of
new features.

Signed-off-by: Damien George <damien@micropython.org>

ports/zephyr/mpconfigport.h

@@ -31,6 +31,11 @@
 #include <zephyr/kernel.h>
 #include <zephyr/drivers/spi.h>
 
+// Use the basic configuration level to get a balance between size and features.
+#ifndef MICROPY_CONFIG_ROM_LEVEL
+#define MICROPY_CONFIG_ROM_LEVEL (MICROPY_CONFIG_ROM_LEVEL_BASIC_FEATURES)
+#endif
+
 // Usually passed from Makefile
 #ifndef MICROPY_HEAP_SIZE
 #define MICROPY_HEAP_SIZE (16 * 1024)
@@ -48,20 +53,11 @@
 #define MICROPY_REPL_AUTO_INDENT    (1)
 #define MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF  (1)
 #define MICROPY_KBD_EXCEPTION       (1)
-#define MICROPY_PY_ASYNC_AWAIT      (0)
 #define MICROPY_PY_BUILTINS_BYTES_HEX (1)
-#define MICROPY_PY_BUILTINS_FILTER  (0)
-#define MICROPY_PY_BUILTINS_PROPERTY (0)
-#define MICROPY_PY_BUILTINS_RANGE_ATTRS (0)
-#define MICROPY_PY_BUILTINS_REVERSED (0)
-#define MICROPY_PY_BUILTINS_STR_COUNT (0)
 #define MICROPY_PY_BUILTINS_MEMORYVIEW (1)
 #define MICROPY_PY_BUILTINS_HELP    (1)
 #define MICROPY_PY_BUILTINS_HELP_TEXT zephyr_help_text
-#define MICROPY_PY_ARRAY            (0)
 #define MICROPY_PY_ARRAY_SLICE_ASSIGN (1)
-#define MICROPY_PY_COLLECTIONS      (0)
-#define MICROPY_PY_CMATH            (0)
 #define MICROPY_PY_MICROPYTHON_MEM_INFO (1)
 #define MICROPY_PY_MACHINE          (1)
 #define MICROPY_PY_MACHINE_INCLUDEFILE "ports/zephyr/modmachine.c"
@@ -80,7 +76,6 @@
 #endif
 #define MICROPY_PY_MACHINE_PWM      (1)
 #define MICROPY_PY_MACHINE_PWM_INCLUDEFILE "ports/zephyr/machine_pwm.c"
-#define MICROPY_PY_STRUCT           (0)
 #ifdef CONFIG_NETWORKING
 // If we have networking, we likely want errno comfort
 #define MICROPY_PY_ERRNO            (1)
@@ -96,7 +91,6 @@
 #define MICROPY_PY_BINASCII         (1)
 #define MICROPY_PY_HASHLIB          (1)
 #define MICROPY_PY_OS               (1)
-#define MICROPY_PY_TIME             (1)
 #define MICROPY_PY_TIME_TIME_TIME_NS (1)
 #define MICROPY_PY_TIME_INCLUDEFILE "ports/zephyr/modtime.c"
 #define MICROPY_PY_ZEPHYR           (1)
@@ -117,11 +111,6 @@
 #define MICROPY_FATFS_RPATH            (2)
 #define MICROPY_FATFS_NORTC            (1)
 
-// Saving extra crumbs to make sure binary fits in 128K
-#define MICROPY_COMP_CONST_FOLDING  (0)
-#define MICROPY_COMP_CONST (0)
-#define MICROPY_COMP_DOUBLE_TUPLE_ASSIGN (0)
-
 // When CONFIG_THREAD_CUSTOM_DATA is enabled, MICROPY_PY_THREAD is enabled automatically
 #ifdef CONFIG_THREAD_CUSTOM_DATA
 #define MICROPY_PY_THREAD                   (1)