freeze rfm9x and BusDevice, remove many built-in modules

Author: jerryneedell

.gitmodules

@@ -147,3 +147,6 @@
 [submodule "ports/esp32s2/esp-idf"]
 	path = ports/esp32s2/esp-idf
 	url = https://github.com/tannewt/esp-idf.git
+[submodule "frozen/Adafruit_CircuitPython_RFM9x"]
+	path = frozen/Adafruit_CircuitPython_RFM9x
+	url = https://github.com/adafruit/Adafruit_CircuitPython_RFM9x.git

frozen/Adafruit_CircuitPython_RFM9x

@@ -10,4 +10,22 @@ INTERNAL_FLASH_FILESYSTEM = 1
 LONGINT_IMPL = NONE
 CIRCUITPY_FULL_BUILD = 0
 
+
+# A number of modules are removed for RFM9x to make room for frozen libraries.
+# Many I/O functions are not available.
+# math is very large and is also removed.
+CIRCUITPY_ANALOGIO = 0
+CIRCUITPY_PULSEIO = 0
+CIRCUITPY_NEOPIXEL_WRITE = 1
+CIRCUITPY_ROTARYIO = 0
+CIRCUITPY_RTC = 0
+CIRCUITPY_SAMD = 0
+CIRCUITPY_USB_MIDI = 0
+CIRCUITPY_TOUCHIO = 0
+CFLAGS_INLINE_LIMIT = 35
+# Make more room.
 SUPEROPT_GC = 0
+
+# Include these Python libraries in firmware.
+FROZEN_MPY_DIRS += $(TOP)/frozen/Adafruit_CircuitPython_BusDevice
+FROZEN_MPY_DIRS += $(TOP)/frozen/Adafruit_CircuitPython_RFM9x