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/Makefile b/drivers/net/Makefile
index aedb2cc..0aaac6b 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -56,6 +56,7 @@
 obj-$(CONFIG_ETH_SANDBOX) += sandbox.o
 obj-$(CONFIG_ETH_SANDBOX_RAW) += sandbox-raw.o
 obj-$(CONFIG_SH_ETHER) += sh_eth.o
+obj-$(CONFIG_RENESAS_RAVB) += ravb.o
 obj-$(CONFIG_SMC91111) += smc91111.o
 obj-$(CONFIG_SMC911X) += smc911x.o
 obj-$(CONFIG_DRIVER_TI_EMAC) += davinci_emac.o