musb_hdrc: TUSB EVM support

Add basic support for the TUSB6010 EVM board, as connected to H4.
This consists of

  (a)   mostly-generic setup utility, which should be usable on other
        242x boards with a tusb6010 chip;

  (b)   EVM-specific setup for an H4 board stack.

Tested only using PIO; though the DMA timings look plausible.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>