phy: cpcap-usb: Remove some useless code

Axe a clk that is unused in the driver.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20200507203127.202197-1-christophe.jaillet@wanadoo.fr


Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>