usb: musb: provide empty dma_controller_create() in PIO mode
usb: musb: provide empty dma_controller_create() in PIO mode

Add a dma_controller_create() returning NULL so a few ifdefs can
dropped.

Signed-off-by: Sebastian Andrzej Siewior <265264fed90bdf8e813a354375ec16f47ebdb1c5@linutronix.de>
Signed-off-by: Felipe Balbi <94dddeeef08b001e003cce128ddc162a4e2c6cd2@ti.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs