leds: we don't want people to use LED subsystem for vibrations

Remove notes about vibrations, as that is better done using input
subsystem.

Signed-off-by: Pavel Machek <[e-mail]>

Documentation/leds/ledtrig-transient.rst

···
 goes away without deactivating the timer, the hardware will be left in that
 state permanently.
 
-As a specific example of this use-case, let's look at vibrate feature on
-phones. Vibrate function on phones is implemented using PWM pins on SoC or
-PMIC. There is a need to activate one shot timer to control the vibrate
-feature, to prevent user space crashes leaving the phone in vibrate mode
-permanently causing the battery to drain.
-
 Transient trigger addresses the need for one shot timer activation. The
 transient trigger can be enabled and disabled just like the other leds
 triggers.
···
 
 This trigger is intended to be used for the following example use cases:
 
- - Control of vibrate (phones, tablets etc.) hardware by user space app.
  - Use of LED by user space app as activity indicator.
  - Use of LED by user space app as a kind of watchdog indicator -- as
    long as the app is alive, it can keep the LED illuminated, if it dies