tweak musb_hdrc SOC init code

Minor cleanups to omap 2430/34xx/35x musb_hdrc init:

 - num_eps is 16; here, each one is bidirectional
 - use DMA_32BIT_MASK to prevent confusion/errors
 - initialize root port power to reflect 100 mA limit

This still hard-wires some board-specific data, since there
are no hooks through which different boards can provide the
right data to the init code.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>