ARM: dts: imx25: consolidate properties of usbhost1 in dtsi file

The usb port represented by &usbhost1 uses an USB phy internal to the
SoC. We add the phy_type to the base dtsi so the board dts only have to
overwrite it if they use a different configuration. While at it we also
pin the usbhost port to host mode.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>