USB: ehci-omap: Get rid of omap_ehci_init()

As it does almost nothing, get rid of omap_ehci_init()
and move the ehci->caps initialization part into probe().

Also remove the outdated TODO list from header.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>