usb: Remove orphaned UDC drivers

usb: Remove orphaned UDC drivers

These drivers have no way to probe as there are no match tables nor
devices created with a matching name in the kernel tree.

Marvell UDC was only ever supported by board files which were removed
in 2022.

For Marvell U3D, which was added in 2012, the PXA2128 aka MMP3 support
was never upstreamed with board files and only revived in 2019 with DT
support. No U3D DT support has been added since then.

The PLX net2272 driver was formerly used on blackfin. It also has PCI
support, but that appears to be only for a development board which is
likely unused given this device dates back to 2006.

Cc: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20250407191756.3584261-1-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>