ravb: Add support for r8a7795 SoC

This patch supports the r8a7795 SoC by:
- Using two interrupts
  + One for E-MAC
  + One for everything else
  + Both can be handled by the existing common interrupt handler, which
    affords a simpler update to support the new SoC. In future some
    consideration may be given to implementing multiple interrupt handlers
- Limiting the phy speed to 100Mbit/s for the new SoC;
  at this time it is not clear how this restriction may be lifted
  but I hope it will be possible as more information comes to light

Signed-off-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
[horms: reworked]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/renesas/ravb.h

@@ -766,6 +766,11 @@ struct ravb_ptp {
 	struct ravb_ptp_perout perout[N_PER_OUT];
 };
 
+enum ravb_chip_id {
+	RCAR_GEN2,
+	RCAR_GEN3,
+};
+
 struct ravb_private {
 	struct net_device *ndev;
 	struct platform_device *pdev;
@@ -806,6 +811,8 @@ struct ravb_private {
 	int msg_enable;
 	int speed;
 	int duplex;
+	int emac_irq;
+	enum ravb_chip_id chip_id;
 
 	unsigned no_avb_link:1;
 	unsigned avb_link_active_low:1;