target/imx7: Add ahb mem_ap

This allows bus access even when CPU is off.

Change-Id: I2d5c5581cd0169aecb92ac7b610810988a8dcef4
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-on: http://openocd.zylin.com/5032
Tested-by: jenkins
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>

tcl/target/imx7.cfg

@@ -37,4 +37,9 @@ set _TARGETNAME_2 $_CHIPNAME.cpu_m4
 target create $_TARGETNAME_2 cortex_m -dap $_CHIPNAME.dap -ap-num 4 \
         -defer-examine
 
+#
+# AHB mem-ap target
+#
+target create $_CHIPNAME.ahb mem_ap -dap $_CHIPNAME.dap -ap-num 0
+
 targets $_TARGETNAME.0