phy: ti: phy-j721e-wiz: add support for j7200-wiz-10g

j7200-wiz-10g supports 2 reference clocks. However, the
control bits for these clocks is in a separate register that
sits in the System Control register space. Handle that register.
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Link: https://lore.kernel.org/r/20220628122255.24265-7-rogerq@kernel.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>