x86/64: Add support for AMD SOC Ethernet controller

This feature is already supported in kernel. Add definition
and configuration in Makefile of OpenWRT.
It is tested on board Dibbler with processor V1605B.
Dmesg is as below.
--------------------------------------------
[    0.317122] smpboot: CPU0: AMD Ryzen Embedded V1605B with Radeon
Vega Gfx (family: 0x17, model: 0x11, stepping: 0x0)

[    8.227270] libphy: amd-xgbe-mii: probed
[    8.228189] amd-xgbe 0000:02:00.1 eth0: net device enabled
[    8.228999] libphy: amd-xgbe-mii: probed
[    8.229921] amd-xgbe 0000:02:00.2 eth1: net device enabled
.....
[   11.760869] br-lan: port 1(eth0) entered blocking state
[   11.761365] br-lan: port 1(eth0) entered disabled state
[   11.762019] device eth0 entered promiscuous mode
[   11.785285] 8021q: adding VLAN 0 to HW filter on device eth1
[   16.881431] amd-xgbe 0000:02:00.1 eth0: Link is Up - 1Gbps/Full -
flow control off
[   16.882108] br-lan: port 1(eth0) entered blocking state
[   16.882583] br-lan: port 1(eth0) entered forwarding state
[   16.883249] IPv6: ADDRCONF(NETDEV_CHANGE): br-lan: link becomes ready
-----------------------------------------------

Signed-off-by: Zheng Bao <[email protected]>

target/linux/x86/image/64.mk

@@ -1,7 +1,7 @@
 define Device/generic
   DEVICE_TITLE := Generic x86/64
   DEVICE_PACKAGES += kmod-amazon-ena kmod-bnx2 kmod-e1000e kmod-e1000 \
-	kmod-forcedeth kmod-igb kmod-ixgbe kmod-r8169
+	kmod-forcedeth kmod-igb kmod-ixgbe kmod-amd-xgbe kmod-r8169
   GRUB2_VARIANT := generic
 endef
 TARGET_DEVICES += generic

target/linux/x86/modules.mk

@@ -19,6 +19,22 @@ endef
 $(eval $(call KernelPackage,amazon-ena))
 
 
+define KernelPackage/amd-xgbe
+  SUBMENU:=$(NETWORK_DEVICES_MENU)
+  TITLE:=AMD Ethernet on SoC support
+  DEPENDS:=@PCI_SUPPORT @TARGET_x86_64 +kmod-lib-crc32c +kmod-ptp +kmod-libphy
+  KCONFIG:=CONFIG_AMD_XGBE
+  FILES:=$(LINUX_DIR)/drivers/net/ethernet/amd/xgbe/amd-xgbe.ko
+  AUTOLOAD:=$(call AutoLoad,35,amd-xgbe)
+endef
+
+define KernelPackage/amd-xgbe/description
+ Kernel modules for AMD 10GbE Ethernet device on an AMD SoC.
+endef
+
+$(eval $(call KernelPackage,amd-xgbe))
+
+
 define KernelPackage/sound-cs5535audio
   TITLE:=CS5535/CS5536 Audio Controller
   DEPENDS:=@TARGET_x86_geode +kmod-ac97