phy: cadence: Sierra: Prepare driver to add support for multilink configurations

Sierra driver currently supports single link configurations only. Prepare
driver to support multilink multiprotocol configurations along with
different SSC modes.

Signed-off-by: Swapnil Jakhade <sjakhade@cadence.com>
Reviewed-by: Aswath Govindraju <a-govindraju@ti.com>
Link: https://lore.kernel.org/r/20211223060137.9252-3-sjakhade@cadence.com


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