USB: misc: Add USB3503 High-Speed Hub Controller

This patch adds new driver of SMSC USB3503 USB 2.0 hub controller with HSIC
upstream connectivity and three USB 2.0 downstream ports. The specification
can be found from 'http://www.smsc.com/index.php?tid=295&pid=325'.

The current version have been tested very basic features switching the modes,
HUB-MODE and STANDBY-MODE.

Signed-off-by: Dongjin Kim <tobetter@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: misc: fixup smatch WARNING

This patch fixes the warning,

6a099c63650e50ebf7d1259b859a3d230aec4207 [4/10] USB: misc: Add USB3503 High-Speed Hub Controller

drivers/usb/misc/usb3503.c:238 usb3503_probe() error: we previously assumed 'pdata' could be null (see line 196)

Signed-off-by: Dongjin Kim <tobetter@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: misc: usb3503: add dt support

Added device tree support for usb3503 driver and add new document with device tree binding information.

Signed-off-by: Dongjin Kim <tobetter@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: misc: usb3503: Fix compiler warning

This patch fixes the compiler warning of uninitialized variable.

drivers/usb/misc/usb3503.c: In function ‘usb3503_probe’:
drivers/usb/misc/usb3503.c:215:13: warning: ‘mode’ may be used uninitialized
in this function [-Wuninitialized]

Signed-off-by: Dongjin Kim <tobetter@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>