scripts: use adapter_nsrst_delay not deprecated jtag_nsrst_delay

Change-Id: Idf98526d64dcba4d8a5b6910bd3c539756753e8e
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/539
Tested-by: jenkins

tcl/target/stm32f2x.cfg

@@ -28,7 +28,7 @@ if { [info exists WORKAREASIZE] } {
 # that there can be a pretty wide band where things are more or less stable.
 adapter_khz 1000
 
-jtag_nsrst_delay 100
+adapter_nsrst_delay 100
 jtag_ntrst_delay 100
 
 #jtag scan chain