Documentation: leds: remove invalidated information

The contents of the Future Development section of leds-class
Documentation was invalidated when support for LED-private triggers
was merged. Remove this section.

Signed-off-by: Marek Behún <kabel@kernel.org>
Fixes: 93690cd ("leds: trigger: add support for LED-private device...")
Signed-off-by: Pavel Machek <pavel@ucw.cz>

Documentation/leds/leds-class.rst

@@ -177,13 +177,3 @@ The LED Trigger core cannot be a module as the simple trigger functions
 would cause nightmare dependency issues. I see this as a minor issue
 compared to the benefits the simple trigger functionality brings. The
 rest of the LED subsystem can be modular.
-
-
-Future Development
-==================
-
-At the moment, a trigger can't be created specifically for a single LED.
-There are a number of cases where a trigger might only be mappable to a
-particular LED (ACPI?). The addition of triggers provided by the LED driver
-should cover this option and be possible to add without breaking the
-current interface.