staging: usbip: edit Kconfig and rename CONFIG options

Change modules usbip_common_mod to usbip-core and usbip to usbip-host;
edit configuration option help text; rename CONFIG options to use a
USBIP prefix and change COMMON to CORE in both the Kconfig and
Makefiles; edit the menu entries; and edit the driver descriptions.

Signed-off-by: matt mooney <mfm@muteddisk.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>