gcc: Update README: tested on arm (imx233-olinuxino) board

Signed-off-by: Harald Geyer <harald@ccbib.org>
Signed-off-by: Christian Beier <dontmind@freeshell.org>

devel/gcc/README

@@ -4,6 +4,7 @@ To save disk space, this GCC only supports dynamic linking on the target box,
 there are no static libraries shipped except libgcc.a on those architectures
 that need it.
 
-For now, this was only tested on a mips target. Others to be done...
+For now, this was only tested on arm (EABI) and mips targets. Others to be
+done...
 
    Christian Beier <cb@shoutrlabs.com>