ravb: Rename "no_ptp_cfg_active" and "ptp_cfg_active" variables

Rename the variable "no_ptp_cfg_active" with "gptp" and
"ptp_cfg_active" with "ccc_gac" to match the HW features.

There is no functional change.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Suggested-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>