Update .gitmodules

Author: maxpromer

.gitmodules

@@ -17,9 +17,16 @@
 [submodule "lib/nrfx"]
 	path = lib/nrfx
 	url = https://github.com/NordicSemiconductor/nrfx.git
+[submodule "lib/mbedtls"]
+	path = lib/mbedtls
+	url = https://github.com/ARMmbed/mbedtls.git
 [submodule "lib/asf4"]
 	path = lib/asf4
 	url = https://github.com/adafruit/asf4
+	branch = circuitpython
+[submodule "lib/tinyusb"]
+	path = lib/tinyusb
+	url = https://github.com/hathach/tinyusb
 [submodule "lib/mynewt-nimble"]
 	path = lib/mynewt-nimble
 	url = https://github.com/micropython/mynewt-nimble.git