Merge branch 'depends/usb-fixes' into next/soc

This branch was merged into v4.4-rc5 and is needed for the
bcm2836 support. Merging it first to avoid large-scale backmerge
of rc5.

* depends/usb-fixes:
  usb: dwc2: fix kernel oops during driver probe
  usb: phy: mxs: add "fsl,imx6ul-usbphy" compatible string
  usb: gadget: f_midi: fix leak on failed to enqueue out requests
  usb: gadget: f_midi: Transmit data only when IN ep is enabled
  usb: dwc2: make otg clk optional
  usb: dwc2: Return errors from PHY
  usb: dwc2: Make PHY optional
  usb: renesas_usbhs: gadget: Fix NULL pointer dereference in usbhsg_ep_dequeue()
  usb: kconfig: fix warning of select USB_OTG
  usb: gadget: pxa27x: fix suspend callback
  usb: gadget: functionfs: fix missing access_ok checks
  usb: musb: USB_TI_CPPI41_DMA requires dmaengine support