greybus: endo: rename gb_svc

Change the name of "struct gb_svc" to be "struct svc_info".  The
structure now contains only the SVC's serial number and version (and
are place holders anyway).  We will be defining a structure that
represents the SVC for the SVC protocol connection, and I want to
take back that name.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>