USB: add platform glue driver for FSL USB DR controller

Replace FSL USB platform code by simple platform driver for
creation of FSL USB platform devices.

The driver creates platform devices based on the information
from USB nodes in the flat device tree. This is the replacement
for old arch fsl_soc usb code removed by this patch. The driver
uses usual of-style binding, available EHCI-HCD and UDC
drivers can be bound to the created devices. The new of-style
driver additionaly instantiates USB OTG platform device, as the
appropriate USB OTG driver will be added soon.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>