leds: Remove auto blink in 88pm860x

88pm860x supports auto-blink LED in hardware. It messed with
timer trigger. Now disable the auto-blink function.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>