usb: typec: tcpci_rt1711h: Fix vendor setting when set vconn

replace overwrite whole register with update bits

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Gene Chen <gene_chen@richtek.com>
Link: https://lore.kernel.org/r/20220805071714.150882-3-gene.chen.richtek@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>