board: readme.txt for Intel Galileo Gen 1/2

Created a readme.txt for the Intel Galileo Gen 1/2 that describes,

 * How to build for the Intel Galileo Gen 1/2
 * How to access the console on the Intel Galileo Gen 1/2

Signed-off-by: Ray Kinsella <ray.kinsella@intel.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

board/intel/galileo/readme.txt

@@ -0,0 +1,52 @@
+
+Intel Galileo Gen 1/2
+
+Intro
+============
+
+These instructions apply to both the Intel Galileo Gen 1/2 development boards
+based on the Intel Quark X1000.
+
+How to build
+============
+
+Apply the defconfig for the Intel Galileo Gen 1/2
+
+ $ make galileo_defconfig
+
+Add any additional packages required and build.
+
+ $ make
+
+The build process will create a SD card image and place it in output/images.
+
+ $ ls -lh output/images/sdcard.img
+ -rw-r--r--. 1 foo foo 11M Nov 17 16:19 output/images/sdcard.img
+
+Write the image to an mSD card, insert into the Galileo and power on.
+
+ $ dd if=output/images/sdcard.img of=/dev/mmcblk0; sync
+
+Accessing the console
+=====================
+
+During power-on the console will become available on the Galileo's ttyS1. This 
+may be accessed as follows.
+
+ * Galileo Gen 1
+
+	http://clayskits.com/products/galileo-gen-1-serial-cable
+
+	A USB to RS-232 to 3.5mm Jack cable is required. Connect to the 3.5mm
+	Jack next to the Ethernet Header.
+
+ * Galileo Gen 2
+
+	http://www.ftdichip.com/Products/Cables/USBTTLSerial.htm
+
+	A FTDI TTL-232R-3V3 cable may be used to connect to the FTDI header 
+	next to the Ethernet connector on the Galileo Gen 2. 
+
+The console should now be visible at 115200 baud.
+
+ $ picocom -b 115200 /dev/ttyUSB0