ravb: Add ptp_cfg_active to struct ravb_hw_info

There are some H/W differences for the gPTP feature between
R-Car Gen3, R-Car Gen2, and RZ/G2L as below.

1) On R-Car Gen3, gPTP support is active in config mode.
2) On R-Car Gen2, gPTP support is not active in config mode.
3) RZ/G2L does not support the gPTP feature.

Add a ptp_cfg_active hw feature bit to struct ravb_hw_info for
supporting gPTP active in config mode for R-Car Gen3.
This patch also removes enum ravb_chip_id, chip_id from both
struct ravb_hw_info and struct ravb_private, as it is unused.

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