usb: host: ehci-vf: Remove hardcoded USB host client configuration

The current ehci-vf USB driver for Vybrid hardcodes the USB host
and client functionality. Remove this.

Reported-by: Santhosh Kumar Janardhanam <santhosh.kj@hcl.com>
Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>