MIPS: Netlogic: use ehci-platform driver

The EHCI platform driver is suitable for use by the Netlogic XLR platform
since there is nothing specific that the EHCI XLR platform driver does.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>