meta-phosphor: add nfs distro feature

Add include files for NFS distro features, which enables NFS kernel
configuration and utility to mount NFS from BMC.

Tested:
1. Check if CONFIG_NFS_* are enabled
$ zcat /proc/config.gz | grep NFS
2. Mount remote NFS folder
$ mount -t nfs 10.10.130.2:/tftpboot/ISO_file /tmp/mount_nfs

Change-Id: I015f4f6ed9c5b60573340233aee1f781aa0c573a
Signed-off-by: Thang Q. Nguyen <thang@os.amperecomputing.com>
diff --git a/meta-phosphor/conf/distro/include/nfs.inc b/meta-phosphor/conf/distro/include/nfs.inc
new file mode 100644
index 0000000..de28475
--- /dev/null
+++ b/meta-phosphor/conf/distro/include/nfs.inc
@@ -0,0 +1,2 @@
+DISTRO_FEATURES += "nfs"
+DISTROOVERRIDES .= ":df-nfs"
diff --git a/meta-phosphor/recipes-core/util-linux/util-linux_%.bbappend b/meta-phosphor/recipes-core/util-linux/util-linux_%.bbappend
new file mode 100644
index 0000000..26c6a10
--- /dev/null
+++ b/meta-phosphor/recipes-core/util-linux/util-linux_%.bbappend
@@ -0,0 +1,2 @@
+PACKAGES:append = " ${PN}-mount"
+RDEPENDS:${PN}-mount:append:class-target:df-nfs = " nfs-utils-mount"
diff --git a/meta-phosphor/recipes-kernel/linux/linux-%.bbappend b/meta-phosphor/recipes-kernel/linux/linux-%.bbappend
index 1e00815..2f75904 100644
--- a/meta-phosphor/recipes-kernel/linux/linux-%.bbappend
+++ b/meta-phosphor/recipes-kernel/linux/linux-%.bbappend
@@ -5,3 +5,7 @@
 SRC_URI:append:df-mctp = " \
         file://mctp/mctp.scc \
         "
+SRC_URI:append:df-nfs = " \
+        file://nfs/nfs.scc \
+        file://nfs/nfs.cfg \
+        "
diff --git a/meta-phosphor/recipes-kernel/linux/nfs/nfs.cfg b/meta-phosphor/recipes-kernel/linux/nfs/nfs.cfg
new file mode 100644
index 0000000..24a387d
--- /dev/null
+++ b/meta-phosphor/recipes-kernel/linux/nfs/nfs.cfg
@@ -0,0 +1,5 @@
+CONFIG_NFS_FS=y
+CONFIG_NFS_V3=y
+CONFIG_NFS_V4=y
+CONFIG_NFS_COMMON=y
+CONFIG_NFSD=y
diff --git a/meta-phosphor/recipes-kernel/linux/nfs/nfs.scc b/meta-phosphor/recipes-kernel/linux/nfs/nfs.scc
new file mode 100644
index 0000000..7d1acba
--- /dev/null
+++ b/meta-phosphor/recipes-kernel/linux/nfs/nfs.scc
@@ -0,0 +1,3 @@
+define KFEATURE_DESCRIPTION "Enable NFS"
+
+kconf non-hardware nfs.cfg