phy: zynqmp: Handle the clock enable/disable properly

The current driver is not handling the clock enable/disable operations
properly. The clocks need to be handled correctly by enabling or
disabling at appropriate places. This patch adds code to handle the
same.

Signed-off-by: Manish Narani <manish.narani@xilinx.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/1616588325-95602-1-git-send-email-manish.narani@xilinx.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>