usb: typec: intel_pmc_mux: enable sysfs usb role access

The OS, such as ChromeOS, uses Android Runtime to run Android applications.
This necessitates supporting tools, for example, Android Debugger (ADB).
On host to host setup xHC.DbC shall support ADB with USB. This requires
user space to control USB roles.

Enable user space control to modify the USB Type-C role. At run time
it will create a role attribute in /sys/class/usb_role/<switch>/.
Attribute can be modified based on the values suggested in the
Documentation/ABI/testing/sysfs-class-usb_role.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Uday M Bhat <uday.m.bhat@intel.com>
Link: https://lore.kernel.org/r/20230906072717.32485-1-uday.m.bhat@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>