xilinx: common: Add Makefile to common folder

There is no need to reference files in common folder back. Simply adding
Makefile to this folder does the job because this "common" location is
already wired in main Makefile.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/board/xilinx/common/Makefile b/board/xilinx/common/Makefile
new file mode 100644
index 0000000..3600da4
--- /dev/null
+++ b/board/xilinx/common/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# (C) Copyright 2020 Xilinx, Inc.
+# Michal Simek <michal.simek@xilinx.com>
+#
+
+obj-y	+= board.o
diff --git a/board/xilinx/versal/Makefile b/board/xilinx/versal/Makefile
index 90e0343..4a46ca0 100644
--- a/board/xilinx/versal/Makefile
+++ b/board/xilinx/versal/Makefile
@@ -6,4 +6,3 @@
 
 obj-y	:= board.o
 obj-$(CONFIG_CMD_VERSAL)	+= cmds.o
-obj-y	+= ../common/board.o
diff --git a/board/xilinx/zynq/Makefile b/board/xilinx/zynq/Makefile
index 096a7ac..8566171 100644
--- a/board/xilinx/zynq/Makefile
+++ b/board/xilinx/zynq/Makefile
@@ -4,7 +4,6 @@
 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 
 obj-y	:= board.o
-obj-y	+= ../common/board.o
 
 ifneq ($(CONFIG_XILINX_PS_INIT_FILE),"")
 PS_INIT_FILE := $(shell cd $(srctree); readlink -f $(CONFIG_XILINX_PS_INIT_FILE))
diff --git a/board/xilinx/zynqmp/Makefile b/board/xilinx/zynqmp/Makefile
index 398c6aa..7d8277c 100644
--- a/board/xilinx/zynqmp/Makefile
+++ b/board/xilinx/zynqmp/Makefile
@@ -4,7 +4,6 @@
 # Michal Simek <michal.simek@xilinx.com>
 
 obj-y	:= zynqmp.o
-obj-y	+= ../common/board.o
 
 ifneq ($(CONFIG_XILINX_PS_INIT_FILE),"")
 PS_INIT_FILE := $(shell cd $(srctree); readlink -f $(CONFIG_XILINX_PS_INIT_FILE))