ARM: dts: Get rid of incompatible ids for hci-omap USB host nodes

The OMAP EHCI and OHCI controllers are not compatible with drivers
other than "ti,ehci-omap" and "ti,ohci-omap3" respectively, so get
rid of the incompatible ids.

CC: Alan Stern <stern@rowland.harvard.edu>
CC: Nishant Menon <nm@ti.com>
CC: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>