docs: add initial st-link info

Change-Id: I213bf26dec582fd8e273e604d43a6e849599dd50
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/340


Tested-by: jenkins
Reviewed-by: Mathias Küster <kesmtp@freenet.de>

doc/openocd.texi

@@ -421,6 +421,19 @@ Raisonance has an adapter called @b{RLink}.  It exists in a stripped-down form o
 @* Link: @url{http://www.stm32circle.com/resources/stm32primer2.php}
 @end itemize
 
+@section USB ST-LINK based
+ST Micro has an adapter called @b{ST-LINK}.
+They only works with ST Micro chips, notably STM32 and STM8.
+
+@itemize @bullet
+@item @b{ST-LINK}
+@* This is available standalone and as part of some kits, eg. STM32VLDISCOVERY.
+@* Link: @url{http://www.st.com/internet/evalboard/product/219866.jsp}
+@item @b{ST-LINK/V2}
+@* This is available standalone and as part of some kits, eg. STM32F4DISCOVERY.
+@* Link: @url{http://www.st.com/internet/evalboard/product/251168.jsp}
+@end itemize
+
 @section USB Other
 @itemize @bullet
 @item @b{USBprog}
@@ -2564,6 +2577,10 @@ which are not currently documented here.
 @end quotation
 @end deffn
 
+@deffn {Interface Driver} {stlink}
+ST Micro ST-LINK adapter.
+@end deffn
+
 @deffn {Interface Driver} {ZY1000}
 This is the Zylin ZY1000 JTAG debugger.
 @end deffn