ANDROID: GKI: support CONFIG_USB_EHCI_HCD_PLATFORM

Everyone really wants either the PCI or Platform EHCI driver, so build
it in so that all boards don't have to select this as well.

Based on a change from zhang sanshan.

Bug: 160193672
Change-Id: Ie2273b5565003f339a7734f579d35b2f8bb4b0b0
Cc: zhang sanshan <pete.zhang@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>