TCL scripts: update to current "flash bank" syntax

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>