prism: added name support to diag 'leds'.

LEDs can be controlled individually by specifying the name after the mode (e.g.
'prism diag leds blink pon-red').

Not specifying a name applies the mode to all LEDs as before.

When the blink mode is specified, the Hz argument, if specified, comes after the
name. Note that while LEDs can be blinked individually, the rate specified
applies to all blinking LEDs.

LED names can be listed using 'prism diag leds list'.

Change-Id: Ia804ff78081c8226669497eff8ceb696d905a1ff
1 file changed