configs: add altera_socdk_defconfig for Altera Cyclone 5 Development Board

This is largely the same as altera_sockit_defconfig.

It uses a fresher Linux and u-boot than SocKit. It also speeds the
serial port up to 115200.

The post-image script is generalized by adding
BR2_ROOTFS_POST_SCRIPT_ARGS and moving it up the altera directory.
Similarly, the readme is moved up and made more generic.

Signed-off-by: Charles Manning <cdhmanning@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

board/altera/post-image.sh

@@ -1,7 +1,8 @@
 #!/bin/sh
-# post-image.sh for SoCkit
+# post-image.sh for SoCkit/SoCDK
 # 2014, "Roman Diouskine" <roman.diouskine@savoirfairelinux.com>
 # 2014, "Sebastien Bourdelin" <sebastien.bourdelin@savoirfairelinux.com>
 
 # create a DTB file copy with the name expected by the u-boot config
-cp -af $BINARIES_DIR/socfpga_cyclone5_sockit.dtb  $BINARIES_DIR/socfpga.dtb
+# Name of the DTB is passed as the second argument to the script.
+cp -af $BINARIES_DIR/${2}.dtb  $BINARIES_DIR/socfpga.dtb

board/altera/readme.txt

@@ -3,7 +3,8 @@ SoCkit
 Intro
 =====
 
-This is the buildroot board support for the Arrow SoCkit Evaluation Board.
+This is the buildroot board support for the Arrow SoCkit Evaluation Board
+and the Altera Cyclone 5 Development Board.
 
 A good source of information is :
 http://www.rocketboards.org/foswiki/Documentation/ArrowSoCKitEvaluationBoard
@@ -46,6 +47,10 @@ all that is required to bring the SoCkit :
 
   $ make altera_sockit_defconfig
 
+and for the SoC Development Board :
+
+  $ make altera_sockdk_defconfig
+
 Build everything
 ----------------
 
@@ -63,7 +68,7 @@ After building, you should obtain this tree:
     ├── rootfs.ext2
     ├── rootfs.ext3 -> rootfs.ext2
     ├── rootfs.tar
-    ├── socfpga_cyclone5_sockit.dtb
+    ├── socfpga_cyclone5_sockit.dtb or socfpga_cyclone5_socdk.dtb
     ├── socfpga.dtb
     ├── u-boot.img
     ├── u-boot-spl.bin