Instead of having committed files containing a single developer's serials, use
optional includes to include a local config file for each board.
If you have only a single board connected, simply:
$ make -f Makefile.<board> clean all flash
If you have multiple boards connected, make sure to fill in the appropriate
hla_serial in your openocd.<board>.local.cfg file, and then run the same
commands.
The F429i board has the user USB OTG port connected to the HS capable
OTG core, rather than the FS OTG core. It is still only operating in FS
mode, as you need a ULPI phy to use HS mode.