fw/icE1usb: Import firmware for the icE1usb and icE1usb-proto boards

Currently only the icE1usb-proto is supported. Adaptation for the
final production hardware is yet to be done.

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/firmware/ice40-riscv/icE1usb/usb_str_app.txt b/firmware/ice40-riscv/icE1usb/usb_str_app.txt
new file mode 100644
index 0000000..10887d3
--- /dev/null
+++ b/firmware/ice40-riscv/icE1usb/usb_str_app.txt
@@ -0,0 +1,8 @@
+0000000000000000
+osmocom
+icE1usb
+Main
+E1
+Console (control)
+Console (data)
+DFU runtime