Add ingenic_tools/usbboot utility

This is essentially an expanded version of jz4760_tools/usbboot,
able to support both X1000 and JZ4760 CPUs and easily extended to
handle other Ingenic CPUs using the same boot protocol.

Change-Id: I70ce3acc3531d65390c6bbae4d2b3352140acf0a
3 files changed