dt-bindings: phy: cadence-torrent: Add optional input reference clock for PLL1

Add a new optional input reference clock (pll1_refclk) for PLL1.
Update bindings to support dual reference clock multilink configurations.

Signed-off-by: Swapnil Jakhade <sjakhade@cadence.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Link: https://lore.kernel.org/r/20240104133013.2911035-2-sjakhade@cadence.com


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