ARM: OMAP: USB peripheral support on H4

H4 has two peripheral ports, one for "download" and one for OTG.
The one to use is selected through Kconfig.

Also removes some bad whitespace from isp1301_omap.c

NOTE:  not yet working; I suspect there's a clock still turned off
or something like that, since neither port responds.

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