usb: phy: mv_u3d: Remove usb phy driver for mv_u3d

The usb phy driver for mv_u3d got added in v3.7 through commit
a67e76ac ("usb: phy: mv_u3d: Add usb phy driver for mv_u3d"). It
then depended on USB_MV_U3D. And that symbol depended
on CPU_MMP3 at that time. But CPU_MMP3 has never been part of the tree.
This means that this drive was unbuildable when it was added.

In commit 60630c2e

 ("usb: gadget: mv_u3d: drop ARCH dependency")
MV_U3D_PHY was made depended directly on CPU_MMP3. That kept it
unbuildable, of course.

Remove this driver. It can be re-added once its dependencies are part of
the tree.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>