net: ravb: Add Renesas Ethernet RAVB driver

Add driver for the Renesas Ethernet AVB block found in RCar H3/M3.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Cc: Tom Rini <trini@konsulko.com>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Based on work of:
Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>
Takeshi Kihara <takeshi.kihara.df@renesas.com>
Kazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 9cd0d94..d7a33d6 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -225,4 +225,12 @@
 	  This driver provides Rockchip SoCs network support based on the
 	  Synopsys Designware driver.
 
+config RENESAS_RAVB
+	bool "Renesas Ethernet AVB MAC"
+	depends on DM_ETH && RCAR_GEN3
+	select PHYLIB
+	help
+	  This driver implements support for the Ethernet AVB block in
+	  Renesas M3 and H3 SoCs.
+
 endif # NETDEVICES