nxp: ddr driver enablement for nxp layerscape soc

DDR driver for NXP layerscape SoC(s):
 - lx2160aqds
 - lx2162aqds
 - lx2160ardb
 - Other Board with SoC(s) like ls1046a, ls1043a etc;
	-- These other boards are not verified yet.
Signed-off-by: Rajesh Bhagat <rajesh.bhagat@nxp.com>
Signed-off-by: York Sun <york.sun@nxp.com>
Signed-off-by: Udit Agarwal <udit.agarwal@nxp.com>
Signed-off-by: Pankaj Gupta <pankaj.gupta@nxp.com>
Change-Id: Ic84a63cb30eba054f432d479862cd4d1097cbbaf

drivers/nxp/ddr/phy-gen2/ddrphy.mk

+#
+# Copyright 2021 NXP
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+#
+#-----------------------------------------------------------------------------
+
+# SNPS ddr phy driver files
+
+DDR_PHY_C  =
+DDR_PHY_H  =
+
+$(DDR_PHY_C): $(DDR_PHY_H) $(COMMON_HDRS) src
+	@cp -r "$(DDR_PHY_PATH)/$@" "$(SRC_DIR)/$@"
+
+$(DDR_PHY_H): src
+	@cp -r "$(DDR_PHY_PATH)/$@" "$(SRC_DIR)/$@"
+
+#------------------------------------------------