usb: ehci-mx6: Pass PHY address to usb_*_phy*()

Instead of passing ad-hoc index to USB PHY handling functions and then
try and figure out the PHY address, pass in the PHY address itself. For
DM case, this address comes easily from DT. For non-DM case, the previous
method is still present, however the non-DM case will soon be removed.

Fixes: 4de51cc2 ("usb: ehci-mx6: Drop assignment of sequence number")
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Ye Li <ye.li@nxp.com>
Cc: uboot-imx <uboot-imx@nxp.com>