TCL scripts: update to current "flash bank" syntax

While "flash bank" syntax has been changed long ago,
several tcl script are still not fully update.

Fix following cases related with "cfi" driver:
- syntax error: the mandatory <name> parameter is missing
- warning: the <target> parameter is a number, instead of
  the target name
- the comment line above the command does not report
  actual syntax

Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>

tcl/board/imx27ads.cfg

@@ -5,7 +5,8 @@ $_TARGETNAME configure -event gdb-attach { reset init }
 $_TARGETNAME configure -event reset-init { imx27ads_init }
 
 # The IMX27 ADS board has a NOR flash on CS0
-flash_bank cfi 0xc0000000 0x00200000 2 2 0
+set _FLASHNAME $_CHIPNAME.flash
+flash_bank $_FLASHNAME cfi 0xc0000000 0x00200000 2 2 $_TARGETNAME
 
 proc imx27ads_init { } {
 	# This setup puts RAM at 0xA0000000