tools: kwbimage: Add support for a new DATA_DELAY command

tools: kwbimage: Add support for a new DATA_DELAY command

This command is supported only by v1 images and specifies a milliseconds
delay after executing some set of DATA commands. The special string value
SDRAM_SETUP instructs BootROM to setup SDRAM controller instead of
executing delay. SDRAM_SETUP may be specified only once and after the
last DATA command.

Signed-off-by: Pali Rohár <[email protected]>
Reviewed-by: Marek Behún <[email protected]>
Reviewed-by: Chris Packham <[email protected]>
Reviewed-by: Stefan Roese <[email protected]>
Tested-by: Chris Packham <[email protected]>