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/target/at91sam9260_ext_RAM_ext_flash.cfg

@@ -54,7 +54,7 @@ $_TARGETNAME configure -event reset-deassert-post {at91sam_init}
 
 
 # Flash configuration
-#flash bank cfi <base> <size> <chip width> <bus width> <target#>
+#flash bank <name> cfi <base> <size> <chip width> <bus width> <target>
 set _FLASHNAME $_CHIPNAME.flash
 flash bank $_FLASHNAME cfi 0x10000000 0x01000000 2 2 $_TARGETNAME