ARM: sunxi: make the leds' names conform to the current naming convention

Quoting from Documentation/leds/leds-class.txt:

    LED Device Naming
    =================

    Is currently of the form:

    "devicename:colour:function"

Signed-off-by: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>