drivers/net/phy/m88e1512: Add new driver for Marvell PHY 88E1512

This driver enables the usage of an external Marvell PHY 88E1512 which
should be connected to a SOC internal MAC controller. In a first step it
is only the framework of the driver. Functionality will follow with a
second patch.

Change-Id: I24011860caa7bb206770f9779eb34b689293db10
Signed-off-by: Mario Scheithauer <mario.scheithauer@siemens.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/69384
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/drivers/net/phy/m88e1512/Kconfig

@@ -0,0 +1,5 @@
+config DRIVERS_ETH_PHY_M88E1512
+	bool
+	default n
+	help
+	  Enable support for external Marvell PHY chip 88E1512.

src/drivers/net/phy/m88e1512/Makefile.inc

@@ -0,0 +1 @@
+ramstage-$(CONFIG_DRIVERS_ETH_PHY_M88E1512) += m88e1512.c

src/drivers/net/phy/m88e1512/m88e1512.c

@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <device/device.h>
+
+static void m88e1512_init(struct device *dev)
+{
+}
+
+struct device_operations m88e1512_ops = {
+	.read_resources = noop_read_resources,
+	.set_resources  = noop_set_resources,
+	.init           = m88e1512_init,
+};
+
+struct chip_operations drivers_net_phy_m88e1512_ops = {
+	CHIP_NAME("88E1512")
+};