USB: Set CONFIG_USB_EHCI_BIG_ENDIAN_MMIO/_DESC in usb/host/Kconfig

Now select the big-endian configuration options
CONFIG_USB_EHCI_BIG_ENDIAN_MMIO and CONFIG_USB_EHCI_BIG_ENDIAN_DESC in
the usb host Kconfig file and not in the platform Kconfig files.

Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>