phy: cadence-torrent: Add separate functions for reusable code

Torrent PHY driver currently supports single link DP configuration.
Prepare driver to support multilink DP configurations by adding
separate functions for common initialization sequence.

Signed-off-by: Swapnil Jakhade <sjakhade@cadence.com>
Reviewed-by: Kishon Vijay Abraham I <kishon@ti.com>
Link: https://lore.kernel.org/r/20210728145454.15945-8-sjakhade@cadence.com


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