BACKPORT: usb: xhci: plat: Add USB 3.0 phy support

For Realtek SoC, the usb xhci uses different driver for u2phy and u3phy.
Therefore, add a hook to retrieve the USB 3.0 PHY to XHCI plat.

Signed-off-by: Stanley Chang <stanley_chang@realtek.com>
Link: https://lore.kernel.org/r/20230407060731.20537-1-stanley_chang@realtek.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Bug: 286930662
(cherry picked from commit 9134c1fd
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

 master)
Change-Id: I5dfaebcb5090050ed01a2aca06b5b27993cb1edb
Signed-off-by: Stanley Chang <stanley_chang@realtek.com>