phy: tegra: xusb: Enable usb role switch attribute

This patch enables the usb-role-switch attribute and lets users check
the current device role of the otg capability ports

Signed-off-by: Wayne Chang <waynec@nvidia.com>
Signed-off-by: Haotien Hsu <haotienh@nvidia.com>
Link: https://lore.kernel.org/r/20220928125640.2219402-1-haotienh@nvidia.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>