phy: cadence-torrent: Implement PHY configure APIs

Add support for PHY configuration APIs. These will mainly reconfigure
link rate, number of lanes, voltage swing and pre-emphasis values.

Signed-off-by: Swapnil Jakhade <sjakhade@cadence.com>
Signed-off-by: Yuti Amonkar <yamonkar@cadence.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>