doc: zynq: Describe status of zc770-xm011

zc770-xm011 is also added and supported. Reflect this in README.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>

doc/README.zynq

@@ -57,7 +57,7 @@ bootmode strings at runtime.
 
 - Added basic board configurations support.
 - Added zynq u-boot bsp code - arch/arm/cpu/armv7/zynq
-- Added zynq boards named - zc70x, zed, microzed, zc770_xm010, zc770_xm012, zc770_xm013
+- Added zynq boards named - zc70x, zed, microzed, zc770_xm010/xm011/xm012/xm013
 - Added zynq drivers:
   serial - drivers/serial/serial_zynq.c
   net - drivers/net/zynq_gem.c
@@ -72,7 +72,6 @@ bootmode strings at runtime.
 
 6. TODO
 
-- Add zynq boards support - zc770_xm011
 - Add FDT support on individual drivers
 
 [1] http://www.xilinx.com/products/boards-and-kits/EK-Z7-ZC702-G.htm