initial buildroot for linux 5.15

boot/mv-ddr-marvell/Config.in

@@ -0,0 +1,10 @@
+config BR2_TARGET_MV_DDR_MARVELL
+	bool "mv-ddr-marvell"
+	depends on BR2_aarch64
+	help
+	  Marvell keeps algorithms for DDR training in a separate
+	  repository. This code is not built separately, it is needed
+	  as a dependency to build ATF firmware for Marvell Armada 7040
+	  and 8040 SoCs.
+
+	  https://github.com/MarvellEmbeddedProcessors/mv-ddr-marvell/

boot/mv-ddr-marvell/mv-ddr-marvell.hash

@@ -0,0 +1,3 @@
+# Locally calculated
+sha256  bfab74a625d65238c569b9df282b55c0fc9a1e2d3decedcf194d44774df2ede4  mv-ddr-marvell-305d923e6bc4236cd3b902f6679b0aef9e5fa52d.tar.gz
+sha256  48bb930b6fbc3f5db72e29c849b096df3868e4a6d2bdc0e2dd3365c768241cd5  ddr3_init.c

boot/mv-ddr-marvell/mv-ddr-marvell.mk

@@ -0,0 +1,13 @@
+################################################################################
+#
+# mv-ddr-marvell
+#
+################################################################################
+
+# This is the latest commit on mv-ddr-devel as of 20201207
+MV_DDR_MARVELL_VERSION = 305d923e6bc4236cd3b902f6679b0aef9e5fa52d
+MV_DDR_MARVELL_SITE = $(call github,MarvellEmbeddedProcessors,mv-ddr-marvell,$(MV_DDR_MARVELL_VERSION))
+MV_DDR_MARVELL_LICENSE = GPL-2.0+ or LGPL-2.1 with freertos-exception-2.0, BSD-3-Clause, Marvell Commercial
+MV_DDR_MARVELL_LICENSE_FILES = ddr3_init.c
+
+$(eval $(generic-package))